"i belive the only major things to backdate it is move the air compressor (not sure to where but i remember reading that it had been moved several times) and put a differn style smokebox cover on it...and the switch to wood cab....and stephenson valve gear, tho i think you could just remove the walcherts and get the right look"
While the boiler shell, frame, drivers and tender tank are basically original, virtually everything else would need to be replaced to back-date it to C&N. The smokebox was modified, hand rails were complete different, running boards and cab floor different size and location, etc. Even the check valves were in a different place (it originally injected in the top of the boiler inside the cab right over the firebox). One of the hardest parts to find would be the New York Duplex No. 2 air pump. Even the tender would need to be replaced. The tank has been highly modified (flair cut off, patches added), and the frame and trucks are C&S. As Mike Trent already noted, much of the historic fabric of this locomotive reflects it's years on the C&S and RGS. The appearance it had for the longest time is as it left the RGS, but lettered for C&N 30.
While I would like to see it as it appeared in 1898, I don't want to see all the C&S and RGS parts lost for what would essentially be a replica. The better solution would be to build the replica from the ground up, and keep the historical artifact intact to the extent practical.
Here is how it looked at one point in the early 1900's. It still injects over the firebox, and has original handrails (although they have been removed from the smokebox front), but is on at least its second cab, stack, and smokebox front, and third running boards (first were very low - probably frame-mounted, second were on stilts above the original brackets).
