1. #1998 had the rust bug in the wheelhouses, front valance, quarter panels, rocker areas, jambs, underbelly frames, etc. You name a typical area, and it had rust there. I've only touched about 1/4 of what was done to #1998.
2. #6650 was pretty bashed in, but had some salvageable parts. I have more pictures of cut away sections that I'll post on the blog today or tomorrow, but the best pictures are in the Provamo registry. All of my parts pretty much came from #6650, which isn't a bad thing.
My personal opinion, knowing the previous owner, is that he considered only one worth saving for economic reasons. I'm sure that they both could have been saved, but it was probably more cost effective to part one car out and rebuild the one he liked. The nice (and frustrating) thing about most of this is that I got most of the L-model parts for a pre-L. I'll get into that later.
For those of you who might be doing this, I can say that you want to drill out spot welds as much as possible and avoid cutting panels. Most panels have seams that are useful. Not all of my seams were separated by drilling out spot welds, but I'd say 90% were.