All-
Something ain’t adding up.
First of all, I agree with Louis….it cannot be a 4-2-0….the main rod is at such an angle that it could not connect to a driver far enough back to make it a 4-2-0.
I would guess that the 4-2-0 that the Q had would have looked very much like the Pioneer, if it wasn’t in fact a sister locomotive from the same road. From what I have been able to research the Pioneer was only leased from the G&CU, and at that for a short time, and never was renamed as a Aurora Branch, Chicago & Aurora,
Or CB&Q locomotive.
Second, the photo has to be very early….the appearance of the pilot wheels, the inclined cylinders, and the condition of the engine suggest 1850s or 1860s.
The Newberry has detailed maintenance records (two pages of a ledger for each locomotive) that specify all the work done on each engine down to replacement of the headlight, cowcatcher, etc. and they do cover the early years (not the 1880s where it would have helped to track down the D1 Camelbacks!!!).
From Rupert’s Numerical Roster and other sources it doesn’t seem like there was any number 275 on the roster until an A2 was built in 1990 by Pittsburgh and later a L1 by Rogers as a B&MR number in 1891.
Charlie