Hi Tom, thanks for uploading this video. As I told you, I'm trying to build a Jinty in 7 /4", so I was very curious about yours. However, it looks like they're completely different. The plans I have are by someone called Richard Gomersall, and supposedly are from the early 1990's. The biggest difference I could see is that the cylinders on my plans are arranged with a single steam chest vertically between the two cylinders. I'm looking forward to learning more about yours as you post more videos.
First step would always be to join a club and get involved, that wouldn’t be expensive, after that it can be a slow drip feed, buying materials at the pace you build, or buy a loco that needs rebuilding for a bit more, or most expensive by buying a running loco.