I'm sure this has been asked before so forgive me but pretty new to this. I have a guy who has some Atlas O scale and MTH O scale 2 rail rolling stock he just wants to give to me. One MTH car is a Denver Rockies theme. Thats the main reason for this question, the wife and I are huge fans of the Rockies. Going to take that one no matter what the answer is to my questions. I'm running Lionel trains on fasttrack which you know is 3 rail, will the 2 rail cars run ok on the 3 rail fasttrack? Will the couplers from Atlas and MTH be compatable with the ones from Lionel? My trains are fairly new and I believe so is his rolling stock. He seems to think the couplers are no problem. Last question if they will run on the fastrack, will it cause any problems or wear to the track i should be watching for? Is there anything else I should be asking here about this? Thanks for any information you can give me.