there are some people on ebay selling parts. I cntacted a guy that was parting out a 1980. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4545907797
That is the link to the seller. Contact him and see if he has what you need. I was going to buy the CDI and controller box from him but the 1980 doesn't have the controller. he didn't have the parts listed but gave me a price for them anyway.
Those forks are weird huh? If they ever wear out you gotta buy a whole thing. the tops are welded on the inside were the slides go. and even the rubber wipers can't be removed. Kinda sucks. I think some day I'd like to modify a set of mountain bike forks and find a used mountain bike shock for the rear. it'd have better dampening. I'l let you know how it goes once i get that filter. Don't want to run it and get dirt in a freshly cleaned up carb.