In this video there are some pictures showing the inside of the pedal:https://youtu.be/I1QHo7-9O58
Also here is this JCM800 emulation from years ago:http://tagboardeffects.blogspot.hu/2014 ... ation.html
I am not good at electronics, just building pedals from layouts, but they look close to me. Both of them has the same number and type of capacitors, resistors, trimmers, potentiometers. I am not good at decoding the resistor color codes in the video (would take me an awful lot of time to do it), and I'm on mobile right now and cant read the capacitor values, but I think it's worth a check.