The area that I watch with the Clipperton-L is the filament voltage on the 572B tubes! This filament transformer is NOT center tapped - which I prefer for a multiple tube amplifiers.
The 572-B tubes recommended filament voltage is 6.3 VAC +/- .3 VAC. This means that the tubes should put out full rated power with as little as 6.0 volts on the filaments.
I have seen Clipperton-L with voltages as high as 6.76 volts on the filaments. This was more than the maximum recommended voltage. Eimac did a study and found that for every 3% above the minimum filament voltage required for full output reduced tube life by half. This may be a issue with your supply voltages from local power company.
If you need to reduce this voltage - It's hard to find resistors to do the job since each tube draws 4 amps filament current.
Bob Norgaard has a good explaination for his SB-200 (which also uses 572-B tubes).http://home.gci.net/~rnorgard/ampnotes.html
He made a coil of wire about 30 inches long. They're made of 22 ga. teflon wire. These resistive coils drop the extra voltage. He started with two 36 inch lengths and kept shortening them until he measured about 6.05 to 6.1 volts at the tube sockets. When he got the length right, he just coiled them up and hold them down in the corner with a stick-on and a ty-rap.