A year or two ago, I bought a #0045 Gateman (H0) to use with my "0" trains. A bit small, but closer to scale than the #045. I had the MTH and K-Line "0" versions, but prefer the abrupt action of the Lionels - it seems to go better with the Postwar trains.
Didn't know about the Kader/Bachmann connection. I know the TYCO operating cars from the 60's worked with the Lionel actuating platform. I always figured Frank Pettit had something to do with that after he left Lionel.
Interesting new forum.