Nice little mixer. I am afraid I cannot help with schematics. Tweed data seems hard to come by. I would appreciate a plan view pic of one of the modules.
The super cool catalog available at the Preservation Sound website (http://www.preservationsound.com/?p=6605) has two pages about the BC-82 with some specs. No schematics though.
Many thanks for that Matt. I see the controls are mounted on a steel plate on stand offs from the front panel. Only thing I cannot see is how the PCB is mounted to either the steel plate of the front panel. I don't suppose you would be kind enough to post another photo of the module taken from the other side?