Attached is a copy of the tintype in question. From the RGB image I flipped the image, extracted the Green Channel, converted to a Grayscale image; applied Curves, Noiseware, Unsharpen and saved the image for detail scrutiny, nothing more. No retouching, done in 10 minutes.
In my opinion it appears to be #275, a 4-2-0, probably later in the 1800's than previously thought based on the hand hewn ties and steam crane to the left similar to one used on the Princeton construction project around 1899. Tintypes were used up until the 20th Century. A steam crane was used on the Bureau River Bridge project in 1899 very similar to this cab design. So the date range needs to be considered in dating this image.
I'll leave it to everyone to sort out the details.
Randy Danniel
Mile Post 206 Publishing, Inc.
Mile Post 206 Publishing, Inc
Post Office Box 543
West Burlington, Iowa 52655-0543
