The links I've listed below are some of the most helpful sites I've run accross. A lot of them I use on a daily basis and others I use to locate that hard to find part.
vintagesledpaint.com - The is the best sourcce around for vintage ski doo paint. He also does other brands too!
Bob's TNT page - I've rescued the site for all of us to use
VintageSledders- Ride, learn, share
The Elan page- another rescued site
The old ski doo page - This is hands down the best old ski doo site around
Vintagedoopartsbin - A super good source for NOS parts, beside mine!
A simple PDF test