Chris,
Actually, it's one of PSC's injection molded plastic kits. The body, frame, trucks and most of the details are made up of plastic parts. The handrail, grab irons and brake staff are brass wire. The two tank straps are photo etched brass. The brake rigging is Delrin (I think). The wheels are NWSL.
3rdrail,
Thanks for the compliment. I actually procrastinated the weathering a few days because I was worried I couldn't get the look right.
Erik