95 ft long in total
255 psi operating pressure with 26.5 " cylinders
70,951 pounds rated tractive effort according to steam locomotives .com, which is pretty humble compared to a SD70ace t4 from today, but is slightly more than a Reading T-1.
Looks like Weaver tossed around the idea of making a WM Potomac around 2012, I guess that never panned out.