OK, this may provide a starting point:
This page has a couple of cutaways showing the drive train with turbine and generators, and the diesel in the forward unit: http://www.oil-electric.com/20...brash-ups-gtels.html
And here's a closer shot of a turbine before installation, with some piping detail on one side: https://cdm16694.contentdm.ocl...16694coll20/id/2694/
I have a couple of gas turbine books but have not seen detailed drawings of the turbines themselves. I know that these have been modeled in HO in some detail but not where the maker (Overland) sourced its info.
BTW, I understand that Alco was involved in at least an early experimental model, numbered 50, that was tested on the UP routes but never owned by UP. Obviously the turbine itself was built by GE.