Art Burrill's collection
Union Pacific Builder's Photographs
These are builders photographs of UP4002, which is a Big Boy, UP8000, which is a 4-10-2 and UP9000, one of the three cylindered 4-12-2 locomotives. UP9000 still exists at the Pomona California Fairgrounds. Art had these photographs in his album, but I believe that all three of them were Alco builder's photographs.

[Page eighteen of Art's photographs.]