S. Connor
But I do believe that 4294 was worked harder than 4014, which would mean the boiler has the potential to be very worn out.
Probably wouldn't matter -- or would be only a small part of potential added expense.
It's not really likely that 'harder working' would cause the shell of the boiler to become 'worn out'. Meanwhile, you can assume that all the internals of the boiler would be removed in order for the required testing of the shell, and that most of the internals will need to be replaced or substantially 'worked over' (the expense being much more in the labor than the materials and tools) to get the boiler back in steam. I would agree that any missing piping, gauges, or even systems like feedwater heater components are replaceable, and are not nearly as serious a 'problem' as putting the major pressure and running-gear components of the locomotive back in safe working condition.
That the cab-forward is in 'no worse shape' than 4014 isn't really germane to the situation here. The Big Boy restoration is going to run into the multiple millions. With the railroad's support both in running expenses and in providing a place to operate so large a locomotive after the restoration is complete. Until those things are in place for the SP locomotive, there is effectively zero chance of seeing work to restore it to running condition undertaken. (In my opinion, but I suspect it is a well-justified opinion...)
