They were scarce because they didn't sell well, but 1 of 49 ? I don't remember them being that scarce, and I sold Buicks from '78-'2001. I had a '78 "Century Sport Coupe" version with a 305V8, that I later swapped for a 400 Chevy motor. I somewhat liked the body style because it was unlike the landau top, opera window, waterfall grille trends of the time. The back end design is what made them kinda ugly, but I think a well designed "whale tail" spoiler that wrapped around the sides could make the design lines a lot more cohesive. Lotsa good parts: Quick ratio steering, big front & rear sway bars. Interior is probably vinyl, as there were no leather buckets available back then. I'm glad it isn't closer to home, as I'd be really tempted to have a look, and would likely wind up dragging it home if it was truly rust-free. I still have the 400 motor/ 350 trans in my garage from when I scrapped my '78 10 years ago due to terminal rust. With some skillful redesigning of the rear end it would be a one of the more unique G-bodys.
Bill