What a great idea for you and your daughter to start a forum. I thought I'd share a little about the boiler I have been working on if you don't mind. I have been asking you all sorts of questions via YouTube about dementions and fitting sizes etc. etc. I have also been using a book written by K.N. Harris called "Model Boilers and Boiler Making. Anyway, I started off with my boiler by spending a small fortune on copper pipe and sheeting and began forming the boiler ends. The drawing below is the basic design I am going with although I have made several dimensional changes. I only have a couple photos to share, but I'll add some more later on. Thanks again for all of the help you have given me.