I really just winged the mounting. I gathered all the parts I could find in the junkyard and drilled new holes, bent the "bayonet" slider, etc. The belt is very slightly askew but, as advised here, it has worked just fine.
34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.