Selling my Dad's favorite crane. If interested I can send more photos. I don't know much more than what is listed below. 

Info I have from my Dads records:

It is a P&H model 203A. AC Mack Ser# 1034538, was used in Denver Tramway Corp, 5 ton crane, 21' channel boom, wt approx. 30,760lbs, tires 36x6 (150/762) front 42x16 rear. Mack 4 cylinder down stairs, Buda 4 cylinder BYU1 gas upstairs. Brought from a scrap dealer in Denver in 1991.