Years ago I saw an article on a 1937 DC-3 still in service on Cape Cod airlines, one of the last users in the US. Only the fuselage was original. Due to the deterioration and the extensive stripping of parts, what we had with #315 was a good frame, good wheels, and a repairable boiler. The cab and tender needed re-placement, not to mention over 25 appliances. So what you see is a historic renovation where 60% of what is visible has been replaced. I laugh when I remember it was suggested by a professsional presrvation group we repair the display with lots of bondo!
RGS 42 is in markedly worse shape. It basically has a good cylinder block (cast by a Denver foundry in 1928). It is well-known that the frame is broken in several places. The 1887 boiler is very tired. It could be repaired, but it is doubtful it could run at its old boiler pressure of 160 psi. It would be better to replace it. If the boiler is off the frame, this would be a good time to true up the frame and weld it back together with modern welding technique and material.
Like other small RGS engines, #42 probably broke its frame bucking snow. When this happens, the engine is usually still operable, or at least can get itself to a terminal for repair. Usually such damage is not detected until a mechanical inspection at the engine house.
Our total cost for repair of 315 is $400K and counting, and that is with a relatively good prospect for full repair and dedicated volunteer labor. Because of the many problems with RGS 42 it could cost near $1 million to restore it to its 1939 appearance as a working locomotive. The El Coke postulate is any machinery is reapirable if there is the will and capital to do the job. However, there is a sensible debate as to whether repairs should be initiated on engines as worn-out as #42. It is too bad that such a historical locomotive like 42 is basically good only for display, but it is in good hands and under a roof where the public can view it, so we should be thankful for that.
