Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hi,
New guy here.
I was at a yard sale looking for tools and such. I found some metal files, a ball hammer and this old thing. I paid $30.
This was about a year ago. I finally got around to taking a second look.
Being a hobby machinist, I immediately saw the quality of this engine.
My question(s). If I clean it up, polish the brass and paint properly.What is it worth? It's about 15" high.
I have ordered a PM research #7 to get started in model building. To me at this point, I can sell this and buy another kit or trade?
Just looking for a direction. I noticed you guys hook up steam to your engines. That is appealing to me vs. shop air.
Thanks for your input. I appreciate it.
Jeff