The thing to remember is that Ron at AM isn't a miracle worker, he just appears that way because he normally doesn't announce until his products are at least in transit.
From what he told me a couple of years ago is he now makes the trains here, but sends them off to China for decorating. (Now, I don't know if it was just locomotives or everything. He didn't specify.)There wound up being about a 4-5 month delay for the T&P sets because of the west coast dock strike back then.
Plus, the car I mentioned earlier was the 2012 Fest car, a Soo Line gondola. I took pictures of mine the day it arrived in March (I double-checked now that I'm home) 2014. So, he had to start from scratch to supply these cars, which gives us a rough idea of how long the cycle is.
Rusty