A partial manual for the Heathkit VF-1 which includes the VF-1's schematic and alignment instructions, can be downloaded at the following url:http://bama.edebris.com/manuals/heath/vf-1/
click on the VF-1's PDF file.
Yes, it appears you can subsitution an SO-239 in place of the crystal stocket. Whether the 47K ohm resistor as shown in the VF-1 schematic is required by the Viking or not, you may have to experiment with and without it.
I would review the Viking's manual to determine what connections are required. At a minimum the VF-1 requires 6.3VAC/DC at 450ma and 250 to 350VDC at 20 to 25ma for the plate.