Michael,
Photos of all the locomotives you list are in “The Contemporary Diesel Spotter’s Guide - Second Edition” published by Kalmbach in early 1995. Unfortunately, this information has not been included in later “Guides”. Ulrich has a copy - perhaps he’ll photocopy it for you. You might be able to find a copy on Amazon.com.
Basically, the two Muskingum locomotives are very similar to the Pennsylvania(PC/Conrail) E44, and there is a website providing drawings of PRR electrics (try Google).
The seven Texas Utilities locomotives have cabs based on the GE passenger electrics sent to Taiwan, with a frame and hood similar to a B23-7.
The Black Mesa and Lake Powell bought six new E60C locomotives, the only buyer of them. Models were available from Bachmann and Walthers, and plans were printed in RMC about twenty years ago (I have that copy, but I’d have to search for it). These were tall, box like single ended locomotives.
Deseret Western bought two E60C-2 locomotives. These were double end units that looked like taller versions of Amtrak E60CH locomotives. I don’t know where plans might have been published.
Navajo Mine purchased two ex-Amtrak E60CH locomotives, and fitted frames to raise the pantographs to suit a higher contact wire location. Again, I think RMC published drawings, and Bachmann made a model (in original form). The book above has a photo of the Navajo locomotive.
The wild card in all of this is the Nacional de Mexico, who bought 39 E60C-2 locomotives very similar to the Deseret Western units. They then abandoned the electrification, and these units have been recently finding their way onto the BM&LP, Deseret Western and Navajo Mine railroads, because they are available at low cost. I don’t know where, and how many, have made this move.
Trains covered the BM&LP and Navajo Mine railroads in the October 2000 issue, page 51 “The Lonely Railroads of the Four Corners”. The coal cars are shown, but not wel