Finally got a chance to tear down and start inspecting the boiler, turns out it is an all stainless boiler, and appears to be very little runtime, or the operator was actually diligent about using distilled water! Looks quite good. Odd positioning of the boiler nipples, but I think I can work with them for a layout. May want to weld on another for a larger steam whistle, but that gets into additional issues haha, my buddy who does stainless is just okay haha, not sure I trust a boiler to "just okay." No offense intended to him haha. An odd detail I found was that the sight glass had check valves (completely rusted in place) on both ends of the sight glass. If anyone has any idea why that would be desired, I'd love to know! I was thinking perhaps they were a safety that would cut off flow to the glass in case of a break, but would allow movement at lower pressure differentials and rates. I really want to hydro this, but my boiler feed pump I usually use needs some new rings... Guess the tree of projects will grow lol