I’ve been looking at doing a post phase inverter master volume mod to my Fender Vibrolux. I was wondering about using what was on the Victory V40, since it is a American-style tube amp. It turns out they seem to use a Type-2 Lar-Mar but with a larger value pot, and smaller value safety resistors.
I think the advantage of this setup is that with the resistors in parallel, the lower resistance makes more difference when calculating the total resistance. The better tolerance of the fixed resistors keeps the total grid leak resistors more consistent between the two power tubes, as pot tolerances can be 10-20% of the stated value.