@vileslug local Facebook groups work well, you can either make a post yourself or just keep an eye out for people looking. Had some good experience last year with both
These trains appear to be modeled after the JNR Class D51 steam locomotive, the most mass-manufactured locomotive in Japanese rail history. However, they have a 2-6-4 wheel arrangement similar to the JNR Class C10, rather than the D51's 2-8-2 wheel arrangement.