I think I'm going to get a few questions about this one, although a look at the front of the Deluxe at the graphical links between switches and pots will probably give a good clue how this one works if you aren't already familiar. A quick overview though, this is by no means a Muff, but it does have certain similarities, ie 4 "stages":
Booster > Gain > Gain > Tone and recovery
but with this the stages can be removed individually. So you could have just a booster with tone control if you like by bypassing the two gain stages. Or a spikey gainy monster by removing just the Tone stage. Or any combination that takes your fancy. I'm sure the offboard wiring will be a pain, but no pain no gain eh!
In the meantime, info about the original:
FIX’D FUZZ DELUXE, the hydra-headed dragon of handmade fuzzboxes, boosts & overdrives. Replete with two polar opposite fuzz tones, as well as a fullrange clean boost through heady overdrive and a (wide) tone sculpting stage. It delivers BIG diversity in sound - all in a small footprint package designed specifically for the cramped pedalboard.
The Fix'd Fuzz Deluxe picks up where the old stock Fix'd Fuzz left off and adds more tweakability, like the version used in the Twosome.