My kinda bike!!
I'd clean it up good before you take it to bits. You may find that you don't need to. I know a lot of guys who do needless restoration. Tough to tell from pics but the bike seems to have good patina. Judging by the lack of wear on the Pagusa seat horn, I am guessing it wasn't used much??
Looks like as far as major parts all you need is an exhaust and those are readily available.
Contact Craig and Elaine Vechorik of Bench Mark Works for parts. They have the best supply in the US ad their prices are good. If you need tools contact Ed Korn of Cycle Works. If you want to order parts from Europe, Mark Huggett and Uli's. Of course for genuine, super high quality stuff, any BMW bike dealer can supply you parts. Many are still made by BMW Mobile Tradition
BTW...the pillon pad is worth some cash if in good shape.
PS. There are a ton of sites documenting /2 restos. Just google. Also go to
http://www.vintagebmw.org for the vintage club.
PPS. Your bike is mostly complete, but BMW restos can get expensive quick if it needs work. Its a BMW afterall, and generally things are not cheap...even if they are "cheap".