There really aren't many places with used RV parts around. Generally, RV parts aren't really designed to last and are made cheap. When a salvage place were to factor in the cost of buying a salvage RV, putting man hours into stripping it down, they really don't have many good parts left that are worth anything. It just isn't a money making thing. If you could do the strip down work yourself, then you could probably come out ahead, but even that has no guarantees.
You can check your local Craigslist to see if they have anything, but generally, new RV parts are cheap enough that you can just go that route. Like I was saying with salvage, if a company were to part out an awning from one, the labor cost and percentage of purchase price would probably be as much or more than new.
If you have an awning and just need fabric/parts for it, that's much easier to find.
Good luck in your quest to get it all fixed up!
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR