Rudy at D&R Marine sells copies of the original 2-sided 11" x 17" rigging guide for the 25 (covers bot hK/Cb and Keel models). Doesn't really say much that can't be figured out by looking at boat.
I have created an expanded version of that sheet, it is in booklet form and includes more diagrams and added notes. Also copies of some old sales brochures (sorry, don't have 1977 yet). E-mail me direct for details.