1974 Cougar Mark IV to be exact..................
dunno if this might help,
http://sharkcatamaranclass.org/index.html , stumbled across this website some time ago, was looking at purchasing something similar on e-bay some time ago, not sure if it was a shark or a cougar, but maybe they can direct you to a cougar webpage.
I love collecting info on these old cat models. Is that your boat in the picture? Have you got any Cougar Cat brochures or manuals?
You can place wanted ads here in the classifieds and maybe stir up some parts, someone might have a parts boat taking up space.
Actually, I believe mine is the light blue one in the rear, except it is white instead of wood now, The pic was from 2001 in Clear Lake, IA. That's where I bought it at this spring. I don't need a lot of parts, but might need a few mast and pully parts. Haven't learned how to rig her yet, taking sailing lessons down in Clear Lake tomorrow and Tuesday, weather permitting! Can't wait to get her out!