Nice line-up of E-units, Bob -- An iconic look for sure.
The first UP locomotive to wander in the door here is this U50 doorstop, shown with the auxiliary tender that came with it:
https://dl.dropbox.com/scl/fi/4x6uohk864qrljv87wz2f/U50-01.JPG?rlkey=btz9hvfki6505nd0y1mz7rbb0The tender is a Scale-Craft. I sold it separately not long after it arrived. I had no use for it in the Armour Yellow scheme, and there was no doubt somebody would buy it on eBay for more than it was otherwise worth to me. No regrets.
I thought when this U50 arrived that it was a Penn-Erie, but Pene-Erie castings are aluminum and this one is white-metal. That makes it an LWS version, which did a run of these in white metal long after the very small Penn-Erie run of aluminum versions. Bob calls them pewter, and they may be, but pewter by definition has a lot of tin and lead in it with antimony and other metals. I am not sure about the tin or antimony, but given its weight, the color of the bare metal inside the shell, and wall thickness, I would definitely bet it has a lot of lead. Pewter is not a bad short-hand though. It sure sounds better than "lead-alloy".
Note the outside third rail pickups. I felt a disturbance in the Force upon first looking at it.
Jim