Here's the result. Thank you everyone for your comments and suggestions. This is what makes OGR such a great place to visit. The car did return from Boxcar Bill at the lowest voltage. I did have to raise it to middle level to assure brisk operation.
The best I've been able to do is 4 out of 6 upright. The car is on 0-27 track, and I think you can see the platform is level at the 0-27 setting. I tried the O setting, but the doors would not open. I haven't tried BK's little metal discs yet. I worry that the added size may jam the cans in the loading chute. BK, have you used these before on these non-magnetic milk cans?