You've noticed something that is quite prevalent and it's rather unfortunate. I'm guilty of what you point out as many others are, but I can try to provide a feeble explanation. As a builder of steam locos, it can take quite a lot of time to gather enough pictures and drawings of a steam loco to model it adequately, but this problem is exponentially greater with steam cabs. There are lots of pictures and drawings available for the exterior of steamers, but the opposite can be said of cab interiors. The reference materials required to create a good model of a steam cab interior are very limited as compared to the rest of the loco. I have built a steam cab, but have not released it, and must say that it's been one of the most difficult things that I've attempted creating. Getting the dials and levers to behave correctly have been quite a challenge for me, but I've finally figured just about all of it out. I haven't worked on it in quite awhile, but as I recall, I believe that I got everything working correctly (finally) including the sliding cab windows.
If anyone knows of a good source for reference materials for steam cab interiors, I'd be the first to sing your praises.
Mike
