Just a variation of the Big Muff from a small danish company, all the modifications are well known. But it's a very good mix!
The schematic is included in the manual:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=2ahUKEwiO_JCS2tTeAhWLK1AKHdLECpcQFjAJegQIBBAC&url=http%3A%2F%2Fwww.vulcanmulciber.com%2Fassets%2FManual.pdf&usg=AOvVaw2_dz_7jVQU4CGwCO4R6yyz
I haven't built it and you might notice I'm not sure what some of the controls do! I may have got some of the pots the wrong way around but that's an easy fix if you build this. I think it's right - if you have any issues let us know.