I'm pretty sure the tank and underframe are from the old HObby Line kits from the late 1950s. IIRC, this tooling passed first to Lionel, then to Model Power or somebody. Now it's back with Lionel, though those outrageous handrails are a step down from the original parts. 

I had one of these once, a used piece I picked up at a train show, and I remember certain features like the coupler pockets matched some HObby Line cars I had until I plunged into HOn3 during college. The tank caught my eye because the dome was different from the usual Varney/LifeLike tanks that still clog sale tables. Like nearly all my blue box-quality roster, this one went back to a sale when I purged my roster of this sort of stuff about 30 years ago. Well, most of it. I still have a few blue box cars and similar in case visiting children clamor to run my trains. Not such a great loss if they hit the floor.

Yours Aye,

Garth Groff  🦆