I have seen a few Delta Queens on eBay. (Why do I keep thinking Delta Creams as in Arnott's? lol)
Hot Doggin would be very hard to find, and I have only ever seen one Hang Glider in the flesh. Was actually very nice to play. Super fast!
If you are interested in the playfield layout of Hang Glider, keep your eyes out for "Hi Deal" which is a single player with the same playfield. There are a few of these around.