I'm still not sure that a new boiler would have been less expensive than the repairs. Preserving such a lopsided boiler was definitely worth it. It almost looks like the flanged the backhead by eye, since it rather droops toward the engineer's side.

Interesting comment about boiler steel. When we made the second course patch to replace the rock damaged shell, I did a weld test, welding a coupon of old steel to a coupon of the new steel. When the tensile test was done, the sample tore about an inch away from the weld in the new steel. You can be assured that the old steel has far fewer Toyotas and razor blades in it.