Some folks are too protective of the beloved Lionel name. Not that I don't want it to be also, but MY Lionel died in the 60's. I call things as I see them; thank yourself for not folding when you knew you were right. Except for a few friendly names, my own contact with Lionel as an adult has had a similar flavor to yours fyi. Shifting blame and NO! followed by a refusal to deal with a now upset customer are the new age customer service weapons imo, and it doesn't fly with me. I' m glad to hear you attempt to be bigger than that in your own endeavor.
I'm gladder you're up and running 
The reason you need the common/N wire is transformers are actually isolated from direct contact with your home ac nuetral (simplified version and assumes you made an assumption they would be somehow connected that way since the phasing is related to ac plugs. [it can be quite a puzzle when you take into account over the years U isnt always common, the varible leg changes; etc etc. You will catch on if you wish to, don't rush it, just pace yourself and ask questions. More often than not, the modern breaker will keep you safe, though they can be a PITA too as they can work too well at times 
I actually use my one new age power supply as a diagnostic tool at times too]
Yea; I also had to ask what pita was too 
I only knew it was more than just an alternative sandwich bread 
