I've just written an article about one of my favourite studio equipment manufacturers: Allison Research. For those who haven't heard the name before, this is the company that brought us the Kepex gate and Gain Brain limiter in the early 1970's. Eventually they went on to become "Valley People".
I've scanned and uploaded 11 original Allison documents including brochures, manuals & schematics, and even 2 price lists from 1970 and 1971! There's also a little video of my Gain Brains in action at my studio.