Being a G body car,
like the last Riviera, Park Avenue, leSabre, and Bonneville, the Seville and Eldorado are smaller, and I would not say a living room on wheels. DeVilles were HZ bodies, until the 2000 model year, then moved to the G on a longer wheelbase and wider floor pan. They did share suspension pieces.
A car exposed to salty sea air with rust around the screws anywhere is not a "cream puff" for sure. If you can see rust, there is more beneath the sheet metal surface.
Cadillacs are known to rust on the deck lids along the chrome trim at the bottom.
Caveat emptor, buyer beware.
