There are some things that are hard to find in nice shape for a G body, and that no one offers new. I have looked for years for the stupid window felts for the wide trim option Cutlass with no luck. I can get the ones for a base model, but not a Brougham, Salon or 442. I have had it pretty easy where I live as G bodies were common down here in Florida, but now they are starting to dry up. The ones you do find are usually so beat that there is little to nothing left half the time. Still, it's easier than being an AMC guy. I have an AMC Spirit GT with a 360 swap that I am getting rid of soon because I am tired of it, but I can't find even the simplest parts sometimes. I go months without finding one in a junkyard. Fortunately, I have a large stash of AMC crap to draw from (and an even bigger G body one!), but it is almost impossible to find a rocker panel for one.
I just have to wonder if there is any future to the restoration industry. They seem stuck in the early 70's at newest. You also have to wonder what new cars from today will actually be restorable in the future seeing as how the technology is so complex that it will likely be cost prohibitive to do so, if gasoline is even available when today's cars are classics. The newest cars I can see having any real restoration aftermarket are from the late 90's to maybe mid 2,000's (Mustangs). After that, the Sport Compact thing dried up due to complexity and resistance to modification, and the newer Musclecars have similar issues.