It sounds decent now even for other styles not just that all round gain fizz as it was.
I added a choke and changed about 22 component values (installed sockets, will solder the chosen parts directly on the sockets), and redid a lot of solder spots + changed the very tarnished PCB jack-in connectors. Added four toggle switches to change some gain structure and high end content, nothing fancy, but usable and makes the amp from a very slight cleanish od/stoner rock/fuzzish od to 80s rock, the gain knob is now usable in all its range. Also added a white led to the clean channel and a blue one on the overdrive one.
Some videos with the amp, random takes here and there:
Crate Blue Voodoo (HGE Contraptions modded) warmup
Some other takes:
Crate Blue Voodoo Modded (attenuated) 2
Lightspeed Drive Boost / Crate BV120 modded
Rocktron Ce1 comp boost / Crate BV120
Before: