Steam has updated light and heavy engine files, along with associated misc engine sounds. I know Ring has a recording of a Shay, and may have a few others as well. I don't know as I haven't asked him. My focus is solely on diesels, specifically modern, so that's what my conversation with him was about.
Bottom line is that sounds will be improving across the board for Railpro users. Any news of new recordings is good news for Railpro users, even if it doesn't necessarily work for your modeling time period. That will all come with time.
-Kevin