I think I sort of figured it all out. The bell rings with the whistle switch at low voltage, at higher voltages the prime mover ramps up and the horn blows with the whistle switch. The announcement seems to just happen at low voltage with no apparent trigger, and it is flaky. I don't know what, if anything, would positively trigger it. However, it did ring the bell, toot the horn, and do the announcements, so I suspect that's as good as it gets. This one also has the sound in the unpowered unit.
As far as the major issue, the reverse board was cooked because one of the motor leads was shorted to the motor case (frame ground). A new reverse board fixed that.
The way I test motors is put it up on my JAX blocks and connect DC directly to the motor from a bench supply (after lifting one lead from the motor). If they run fine in both directions that way, I figure the motor is probably not the issue.
Thanks for the insights folks. I was really hoping to get the instructions so I could give them to the owner, but I have to first convince him to not run it with the CW-80, that was wacky here as far as operation. It also hated the variable channel of my TIU, but the MRC PurePower 270 worked fine, as I expected it would. Obviously, this was designed in the days of pure sine wave transformers. 
Marty, if you have the instruction sheet, I'd sure appreciate a scan of it.
