While not as many as Jawa (but I don't check very often), I've found some gems at the dump before too, including my near mint 68 Raleigh Sports that will remain in my stable indefinitely. Others include a mid 90's lugged steel Giant roadie (Allegre or something?) that was ridden maybe 10 miles, a pink Lotus Challenger SX in VGC, an Atala w/ Campy bits..and a few clunkers.

Just don't go there expecting to find them and you will have a better chance. Make friends with the guy who deals with the scrap metal pile and he will hold them off to the side for you when they get dropped off