Knowledge about BK Elec TG-100 amplifier board

I recently was given a Stage Classic TG-10 practice guitar amplifier. The amplifier circuit board is a pre-amp plus a single transistor (?) for the output stage. The pcb has the following info printed on it:

BK Elec. TG-100 1997

I'm thinking of re-purposing/using the preamp board and was wondering if anyone could provide some information about the board eg. schematics, expected power out, wire harness colour coding, etc. TIA