#318's boiler has had a serious attach of metal moths. A replacement is needed. Send lots of cash!
It is my understanding (subject to correction) that at least one attempt, perhaps two, was made to replace the firebox by bringing it up through the ashpan in two pieces; it didn't work. The preferred approach would have been to remove the boiler barrel from the firebox wrapper and instert a one-piece firebox horizontally through the firebox wrapper front. All of that is moot anyway because the barrel itself is tired, and too much has been expended over the years without productive results. Museums are gettign smarter about such things as time goes by, and Federal oversight is making folks take a second look at boilers previously deemed safe because they happened to pass a hydro.
Just a tired locomotive, gentleman, and because we have so many projects vying for our limited dollars, there is no point in throwing any more good money after bad. Railfan wishes not withstanding, not all steam locomotive hulks can or should be returned to operating condition.
Mike