I tried a similar type fuzz inverter in a ranger that I was modding a while back, found that it just didnt sound the way that I liked, the audio was a little on the harsh side.
So I went to a more conventional style of fuzz inverter with the additional resistor under the 68k cathode follower, and plate powered from the low b+ instead. It worked very well with 6550s. those tubes are designed to run between class A and AB1. All they need is a little audio to tickle the grids and they really swing the monkey! They dont very much drive to be happy (6550s)
However if you are running 807s (or 6L6s) or anything else in AB2 you have to be able to push them into a little grid current. A straight fuzz inverter wont do it. You will need an additional stage between the inverter and the AB2 grids to do it or go back to transfoma coupling. A pair of cathode followers would prolly do it (or if you must)
Frank, get ur fets out. A nice triode and a GOOD interstage transfoma would definately be easier
The Slab Bacon