Tom,
I bought a couple books from the Colorado Railroad Museum. One of which turned out to be pretty good. "The 1925 Modern American Locomotive Construction and Operation" by Frederick J. Prior. It is a soft cover reprint. I don't recall the price. I carry it with me to SVRy for reading in the evenings etc. The other has a lot of equations and details, but only goes up to late 1800's. It is a hard cover, 658 pages, "Modern Locomotive Construction, 1892" by J.G.A. Meyer. A lot happened between 1892 and 1925 which this later book lacks.
Too bad you don't live in our area. We have our own "hands-on" training, which is getting better all the time. If you walked into our shop and asked if you could help, you would have members knocking each other down to get to you and put you on 'their' project. We will begin this winter working on the appliances on #20. Air pump, lubricators and reverser. Should be interesting as these appliance haven't operated since the early '60s.
dan