Thanks Allin for the info, now that I've had a chance to evaluate and inventory the condition of the engines, I'll spend some time getting up to speed on the different controls available. The short answer for those keeping track is that cleaning the track (center rail was black) with a Scotchbright pad helped some and then wheel cleaning by jumpering w alligator clips off of an American Flyer PS attached to the roller and ground on the engines using isopropyl alchohol with q-tips to clean wheels allowed me to grade the running condition of each engine, most engines are running fair to excellent.
I do have the TV style MTH remote (see pic) and tried resetting the engine to factory defaults (got the two horn blasts) but that didn't resolve the issue. All that aside I opened up both A units and the dummy A unit does not have a battery compartment which seems to run counter to everything else I've learned thus far about MTH w PS2 so my best guess tells me that the B unit is the one that has the battery compartment. I closed on an auction last night for the matching B unit which has the 4 pin socket on one end and the cable extending out on the other, I'll be able to get to the bottom of this once the unit arrives.
I don't think there's an issue with the remote addressing the engines because the 4-6-0 steamer that I mentioned at the beginning of the thread runs fine since cleaning the track and that engine did not come with the MTH set. The original engine (a Pennsy steam turbine) died several years ago - seeing as this thread has caused some confusion along the way I was going to start a separate post for how to get that one fixed - PS2 board replacement is most likely what needs to happen. But since we're here now is that something I can purchase and replace myself?
