[Attachment(s) from Randy Danniel included below]Louis & Charlie
Never say never......
probably not or might not be.......
If you consider the attached image, the geometry of the pony truck
rear axle and wheel diameter, possible engine driver centerline and
diameter, you can theorize the rail head location. This is not a
perfect perspective correction but it was just an image rotation to
level the engine.
You can also test the theory of #275 being a 4-4-0 if the shadows
really contain driver image data. Each time I look at the shadow
detail I see conflicting details for 2 sets of drivers.
And two issues arise.
The rail head location is different for the pony trucks vs. the drivers.
To obtain a 4-4-0, extending the centerline of the main rod aft from
the crosshead pin might hit the front driver if the rail head location
was the same for both drivers and pony truck.
Using the pony truck rail head location and extending the main rod
centerline slightly further back might produce the argument for a
4-2-0 wheel arrangement.
I think the 3 steam safety valves are a combination of light strikes
or image defects.
All we know for sure is the number is 275. And theories are meant to
be proven.
One thing not taken into consideration is the CB&Q crane at left. It
is lettered CB&Q. See other image.
I would continue to opine this image is later rather than earlier and
#275 is probably Rupert's #275, a 4-4-0 based on the number and that
crane being lettered CB&Q.
Randy