Tiger Valley did make those sideframes, as well as the C truck HiAd version. Alas I haven't talked to Guil Mack in 7 or 8 years and when I last visited him in 2000 he'd just turned 60 and was waffling on whether or not to continue TV models. He had turned his attention to scale live steam parts at that point. I've long misplaced his phone number and the ones on the web are dead ends. His address is your best bet with a letter, as with his huge layout and various rr items on his property, I doubt he would ever move.
TV Models
1070 County Road 23
Phelps, NY 14532
You can try the number.... (315)548-9021