Hi,
The engine length is not the boiler length. I have dimensions on two of the three locos that I have plans for that the distance from the pilot beam (excludes the pilot) to the back of cab. It makes sense that the smokebox front to the pilot beam would be in the 2-5 foot range.
Only one of the drawings has the boiler length. It is interesting to make sure that you are comparing the same measurements. That is why I posted, I tried to make the best guess but was sure errors crept in (such as the 30" supposed to be 39" spacing between the center drivers).
I am working on the assumption that the variations are minor and that the PSC/Kemtron C-16 kit is close to correct for all four. All that would be needed (hopefully) would be different frames and details like cab and tender.
The driver diameter range from 36" to 36.75" depending on the class. 36" is close enough. One inch is about 0.011" in HO scale. I know I would not notice that difference.
I think the same goes for the Class 56.
Thanks again.
Doug vV