Me too. I have stuff which I can't even remember the name of the person who made it, let alone where anyone else would find it.
OK, so who should we volunteer for doing this? 
Not me. But I have been thinking lately that someone should form a restoration team. Their job would be to get hold of ever single halfway decent campaign and make sure that they work with FS2_Open 3.6.9.
Basically that would mean that we'd need people to play through the entire campaign and spot bugs as well as having other people capable of fixing them.
Once the missions are fixed they would have to make sure that they are available from at least two stable FS oriented websites. Hades-Combine is a fairly obvious choice. SectorGame might be another good choice. DW-Hunter's site would be a third but I hesitate to suggest that one seeing as the installer is already eating a big chunk of his bandwidth.
Personally I think this would me a very good project for newbies and moderately experienced tablers/FREDders. We already have a lot of newbies coming into the community and playing campaigns and then finding faults. All you'd have to do is harness that by giving them a large directory of campaigns to play through.
Get the end product linked up in Skippy's campaign list and instead of having newbies wondering what there is to play you could point them at a large database of working missions and campaigns rather than the mess we have at the moment. I know it sounds like a big project but to be honest it's nothing more than what people have been doing in a rather disorganised fashion already.
I'd also like someone (jr2 would be a good choice) to start and update a thread with a list of every campaign which has seen some sort of release. I may have a few other campaigns that he doesn't have and I'm more than happy to add them to his archive if I can find out what they are. For instance I suspect he doesn't have All's Fair in Love and War since I haven't heard anyone mention that campaign since I originally played it.