Disassembled a bit more, this is a very professional build ,I still don't think its factory made but the builder certainly does superior work. the side walls are approx. 1/4" with 64 tubes that I believe are brass or copper, the burner is a very nice fit & cast Iron & made for a lifetime...very heavy duty , I hope I can use it. I had an reducer break off in the bottom side port of the boiler so I need to figure out a way to remove it or tap it in place , I would like to hydraulic test it this weekend.