I will probably get the brian wilson book to start, I will kit bash my current ruby, and figure it out while I am going at it, if I mess up, so what, I am learning lol.
The things I have to learn how to do is, silver soldiering, how to setup and bend the metal properly, measuring, the bolts to hold the non rounded parts together(stays ?). How to figure out if I have enough surface area to generate the steam needed(a ruby is nice about this due to the small cylinders), how thick the boiler walls have to be for safe operation. Once I get good at it I will upside to bigger engines for fun. Probably not ever make running gear, just the boilers for coal firing. (and other engine upgrades, axle pumps, hot water bath returns.), modifications when I get boarded of the current performance of the engine.
BTW, where do you guys get all the small hardware, values, sight glasses etc.