I don’t know the part number - hoping
@FordTechOne can do us a solid here, but I can tell you Lucille has done this for years now. The base just kind of snaps on, and once in a while I’d see the base dancing its way up the antenna! Sometimes I’d stop, other times I’d just keep the speed under 70 until l get to destination. IIRC, last time I think I put a couple drops of Gorilla Glue on it. NOT a lot, I’m talking a couple of really, really small drops from like an eye dropper. That should keep you from losing another one.