fuzzface mod into screwdriver/blackstone

I am going to be modding a fuzzface, for a friend, into a lighter overdrive meant for waveshaping, but wanted to maintain a fuzz circuit or some sort of hybrid. something pretty or dazzling, he asked

I am going to be using mosfets for the transistors and maybe an additional germanium treble booster. I might have to add extra gain stages, according to my study of the blackstone mosfet overdrive. I know that I want to maintain clarity for chords, and I believe that is the way to go. More of a distorted wave form than a real booster. It will be used on a humbucking taylor electric.

Does anybody have any advice. Maybe I need less trim, or to bypass that circuit, but I am not really sure. This is only my 3rd mod and I am still pretty fresh. This is certainly the first mod I am doing without someone else's set design.

Any ideas or advice, to make this low gain fuzzy chord machine would be appreciated.

Here's a link to a site I found with some schematics. If anybody can point out some flaws in my idea, or give me specifics of where to place extra gain stages, please, please help.

here's the link

http://www.runoffgroove.com/multiface.html