Union Pacific Locomotives Athearn HO Scale Cow and Calf

The SW7 was a switch engine made from 1949-1951. The unit with a cab was called a Cow and the one with no cab is called a calf. The Athearn model was made for several decades up until about 2000.
The larger locomotive is a GP which was a road switcher. Which meant they could be used as switch engines or running trains on the mainline. With a different body they were used for high speed passenger trains. Thought I may as well do all my trans as long as I ave them out.