The boiler is very simple to build. The wheels are also simple just requiring different techniques . When I built my mine I had to cut the spokes and strakes from sheet steel. Nowadays you can get them laser cut saving an awful lot of work. As for setting out the spokes ,I had no such luxuries as a dividing head I just made do with a sixty tooth change gear and a strip of aluminum as an indent clamped to my 80 year old lathe 😂 The boiler is about as easy as it gets.A simple round top and just a few fire tubes! No problems. Don’t forget the old adage measure twice cut once . If anyone has problems with boiler building just give me a shout. Tony Wright.