Good luck with the hunting.. ive been after a 1967 Bally ROCKET III  for a few years now. With all the machines ive ever wished for, ive found that all of a sudden one will just fall into your lap ( eventually).
Zipper Flippers though... geez a few years back no one wanted them and then everyone realises that they are just one of the coolest features an EM could have and they become even rarer!!