You can find a Terak emulator here:
http://sourceforge.net/projects/bk-terak-emu/
Schematics of the boards would be nice to find.
I have pics of the boards on bitsavers.
If it ends up you're missing boards, I have a CPU, but
no monitor or keyboard, and at this point it seems about
as likely to finding a kb/monitor for my PERQ.