Yup the usual precautions for meters and transformers, in dishwasher mode, cuz of the steady barrage of high pressure water.
Meters need to be removed even for this approach. I.F. transformers, use a little less direct spray on them.
A little less precaution if you mix about half and half of 409 and Ammonia and a big and small paint brush. Swirl that stuff around all areas above and below, and on the chassis. Rinse well with a gentle spray from a garden hose. Do not overdo the rinse on transformers, just a quick passing OR wipe them with a damp cloth. Front panels look better too, using the ammonia/409. Melts away the nicotine yuk. Won't attack the lettering.
You can polish the knobs with a jeweler's buffing pad on a variable drill using a little car wax. They'll look like new!
Make sure the wife is not home and put the unit in the oven set no higher than 180 degrees and dry the unit for 4 hours. Wait another day or two before applying power.
Fred

Bringing up the HV supply only on the Variac is a safe approach. The variac will not like bringing the entire amplifier up to full voltage. This is a 220 volt variac?
Right now it is best to leave the tubes out of the picture until you have the P.S. happily making HV again.

You're lucky with the solder wick. I never had good success with that. I like the Solder Sucker approach.
I hope you get that beast working. It's a power house amplifier that will happily give a little beyond QRO power.

I am not understanding why a transmatch is mentioned.
The Amplifier has to be brought to resonance for the non-ham frequencies the OP wants to use for MARS. Apparently the 922 is strictly Ham bands only. The transmatch  does its magic after the amplifier is tuned to the operating freq and you want that amplifier to see a 50 ohm load at the output. The transmatch will create something the amplifier wants to see and transfer as much power as possible to the antenna.

Always some very good advice here. It's Summertime and disconnect (Antennas and power) after operating is the best you can do.
If I was not handy in replacing and sourcing what happened to us, end of last Summer, we would have had an out of pocket expense of $1200 from damages from a nearby strike.
The storm came up fast on us and I couldn't power down or turn things off fast enough. I was running up the steps from the shack to start "saving" equipment and it was too late. The lightning was close and the wood burning stove made a snap sound. Discharging I guess. We lost our LED flat screen, it WAS turned off, 2 computers, Ethernet connection/card destroyed, my Flex SDR 1000 radio and another computer developed major mother board problems this past Winter.
Whatever it was came in on the ground side (not protected, but grounded now) of the satellite dishes or the Comcast Cable for our internet. All  these issues are now properly grounded with new 8 foot rods on the tower and all of the RG-6 coax entering the house. The Ham antennas have always had their own protection installed before entering the house. The Ladder Line is on a huge knife switch and that is always disconnected when not in use.
Fred

The injectors may be causing your problem.
I had a Toyota pickemup and the injector noise wiped out 17M HF. I found the wire that grounded all of the leads for the injectors and connected to another part of the engine. Noise went from S-9 to S-1 and then I could enjoy 17M. Apparently the grounding, even though it was originally connected to the engine block, was not good enough. I just experimented until the roar of noise disappeared.
Another problem for your situation may be the alternator. That's usually a whinning sound. The injectors will be a steady hash and will get worse as you rev up the engine.

A blob of solder between the blown traces is all that is needed, and you'll be fine.
There was lightning or severe short circuit. Most likely the latter.

I am thinking that the rage for MORE QRO is that there seems to be a lot more inconsiderate operators on the air now. The ops "playing the game" have to deal with tuner-uppers and ops who like to "Hold the Frequency". Complete silence until you ask if the frequency is in use and then they start to chatter. Or 250khz of band space and QSO's are happening within a 1kc of each other. It takes about 3-4 khz spacing for SSB, and 6khz, for an AM QSO. But no, you hear an AM QSO and there's SSB ops trying their damndest to talk over the AM QSO, either on freq or within 1 khz of the AM QSO.
I know it's a losing battle that whomever can put out the largest signal and be the channel master is the one who wins. Seems like a CB mentality.
Legal QRO, and make improve the antenna.

5/8 wave vertical gives the lower angle of radiation for long distance or DX. Take off angle about 12 degrees. 5/8 wave for a typical ham op becomes manageable 20M up. 40M is an 80 foot tower. Not too many Ham ops can deal with that kind of tower/mast.
Google is getting pretty good with Amateur radio stuff and antennas. Do some research.
As with radials; you always run the longest wires , and as many as you can. (30-60 seems good) If you are willing to put a little more money into radials, then buy vinyl covered, welded fencing. And lay out about 8 of those around the base of the vertical. Get the 4 foot wide 50 feet long and bond together with 2 inch copper strap to the braid of your coax and ground rod. A lot of work and $$ but makes my 40/15/17 meter vert shine. I ran a separate wire extended from the 34 foot 40/15M mast and I have a 5/8 wave 17M antenna. With antenna switcher on the ground and a series coil for matching the 17M ant wire. It's really sweet.

I wouldn't worry about electricity bill.
If it's used as a Ham radio amp it is not a worry. The usual rag chew QSO (SSB) or CW EVEN on the AM mode!
If used as a bootleg pirate radio station then there would be concern.
I am really impressed with the Emtron design and build of the DX-3SP. I sent a request for price and shipping to USA.
Fred

The OP hasn't returned for a bit.
Are you interested in HF antennas or a 2M (144mhz) antenna?

A horizontal antenna like the dipole for 80M would have to be 1/2 wavelength above ground to become directional. 132 feet high. For 40M 66 feet high.
Most Amateurs cannot get dipoles that high. 30-60 feet is about it. And you can still have a lot of fun on the lower bands at those heights.
Same for a Yagi antenna. Yagis are easier to handle from 20M up and 30 feet from the ground is perfect. 60 feet seems to be the best for lower angle radiation.
I think 12 degrees take off angle is the magic bullet for long distance DX.
Now a vertical can obtain low angle easier depending on its length. Usually 5/8 wave long is where the magic begins. 40M would be 80 feet high. So, seems like 20 meters up would be more manageable for that 5/8 wave pie in the sky. It is omni-directional and very noisy for receive.
I have a 34 foot vertical and it is 5/8 wave for 17M and I have a blast with that system.
Fred

Too bad that the Forum info made you sell a possibly good radio.
Get rid of that 300 ohm feedline and rebuild your antenna with a real ladder line and a balanced tuner.
The basic antenna length seems ok for multiband 80-10M...too short for 160M for any tuner.
The fix-all bands with a balun and 75ohm cable is not goodness.
Make it 50 ohm coax and an auto-tuner outside. I don't know what your logistics are to get RF from the shack the antenna.

Excellent Excellent solution. I had one and it will never come down. Well made. But it is a serious install. Must be installed properly and safely. It brackets to the house. Raising and lowering is well designed. Possibly get fancy and motorize it. Expensive! And permanent!!
Push-up masts (telescoping types) can get temperamental and dangerous. Need maintenance to assure nice sliding. Guying is needed. The push-ups get more temperamental when the guying is not balanced.

The multi-band dipole I have been commenting about is almost 65 feet high and same length.
It is a fair DX antenna on 160M. An inverted "L" is much better for DX.
on 80-20 I have had very good success with very good DX. I wasn't concerned about what direction it was pointing. I just threw it up.
It is fed by 150 feet of OWL to a nice Dentron 3KA balanced tuner.

Fred