I just got around to installing the upgrade for my C class Shay. I like the new look for the engines all told, but all the lettering went missing. I uninstalled the old than installed the new, and this was the result:
I tried installing the old one then installing the updated version on top of it, same result. I do not have the B-class shay, if it means anything.
Also, a few quirks I've found repeatedly with these locomotives, one is that when 2 Shays are coupled together in the editor, the "tenders" start to lean off the tracks as soon as you select the locomotive in the scenario. The train below was parked on a curve when it was placed initially.
Also, The 2nd truck of the shay will bounce around and derail if you hit a grade transition at a speed exceeding 15 MPH or so.
The quirks are things I noticed before the upgrade, but I never got around to piping up about them until now

If someone could assist me in remedying the lettering issue I'd appreciate it, the other stuff I merely wanted to point out.