Transistors is unknown NPN Si but I had good results with a BC337 for Q1 and a BC109C Q2.
Here is a quite hilarious product description by "the freaks at DAM"
What? Savage Henry is the sexy new pedal on the sexy block and he is sexay. Created by the freaks at D*A*M. Designed and made by Dirts own fair hands. Circuit 'design' and component selection by Captain Rock.
For fuzz fetishists only. If you like your fuzz tones long and hard or fat and juicy you gotta gets some of this action.
Henry is dead when the sexy knob points to the little skull and x-bones. Touch the sexy knob and make awful sounds. This control is a volume control. It has linear taper thus giving a more interesting degree of saturation and a better preservation of high end frequencies. Mr. Savage is one fuzzy little mother fucker. If you need some kind of sound reference or sonic anchor so you know where this thing is coming from lets say its like a Univox Super Fuzz at its most bulbous and a silicon Fuzz Face chewing on a rusty battery. Its smooth like ground up glass used as a facial exfoliant. Its heavy like doing push-ups with your face.
Q: Will Henry clean up when I roll back my guitars volume control?
A: No. You’ll be offered some interesting sounds but none of these will be of the clean variety.
Q: Oh No! I can hear strange noises when I turn down my guitars volume control. It sounds like a Russian radio station. Is Henry broken?
A: No. Henry is a high gain silicon fuzz box. This is normal. You should be thanking me. You now have a free radio to listen to on those dark lonely nights.
Q: Does Henry like high gain modern pick-ups?
A: No. Henry likes old school shit. Low to medium gain pick-ups are bestest. Ideally below 10k. Henry will have a fight with modern high output pick-ups. P-90’s are good eating.
Q: Will Henry play nice with my 5 watt solid state amp?
A: No. Henry likes the really big fuckers. Vacuum tubes, you have to use them.