Hi artful dodger, I'm still here. I have a 4-6-0 but have yet to get it running well.
I'd be curious what amperage your 4-6-0 AC motor draws at a few different voltages. My motor seems to run well by itself at the test bench but draws more current than I would expect. I don't have any other reference points to determine if my motor has a problem.
Also if you plan on using Lionel 3-rail track make sure your 4-6-0 has blind center drivers. I have seen a variation with all drivers flanged, and I don't believe it would navigate Lionel 3-rail curves.
Chris