I tink you'd find a lot more of the public domain posts than you might expect in the Google cache. Each new thread is assigned a number and that would have been a bit over 81500 by mid-October. There are then posts inside each thread and each is assigned a unique number. You can find these in the source file of the cached page.

If I use "aussiefrogs showthread.php?t=81514" as the Google search term, I get a Citroen Forum post from 5/10/10. Since the images in this thread were inline as opposed to added as thumbnails, it seems they are in the Google cache and can be recovered with the text. Changing the number gives another thread, but recent threads may be incomplete depending on when the page image was cached. Try a few random numbers and see what pops up. 81522 will let you relive someone else's recent trip, but the photos have been lost.

If it's not possible to recover the actual AF database records, then working through the cached posts by thread and post number seems to be one way to recover the information. It would need some structure and co-ordination to deal with a portion of the 80K+ threads, but saving the cached page as single file will preserve it. Extracting the individual posts in each thread from the page source would then be possible. You'd need to collect the cached pages by thread number, perhaps by assinging blocks to people to avoid duplication, and then have a script or code to extract the posts.

Just one idea / suggestion.