Fuzz pedals

[FunkyHotFrog]

Hello DIYmen,

I would like to build a fuzz pedal, but i want to test a lot of schematics before.
Four fuzz pedals are an enigme for me :
MJM London Fuzz (i know that this electonic system is near to a fuzz face pedal but i don't know the exact values of components).
Karl Fuzz Lovepedal (with 3 knobs)
MXR 173 Classic 108 Fuzz (i don't know the schematic)
Voodoo Lab superfuzz (i don't know too)

Somebody could help me please?
(schematics or informations)
Thanks.