I'm not sure. This looks like it might be for a '66 Wildcat.................. https://chicago.craigslist.org/sox/pts/d/buick-fender/6705786275.html
OK V-8 Buick People: Yes it indeed looks like a 66 Wildcat fender. The condition? I wouldn't know until it was media blasted in and out....so, locally, with a close inspection and a cash offer and a vehicle to take it away you just might be able to get a deal.