Silverton Northern #3 and #4 were both Baldwin 10-26E, drawing 18 locomotives. The F&CC/D&RGW C-18s were also drawing 18 locomotives. Although the bell and the sandbox are switched on the C-18 locomotives, the spacing between them is the same. The D&RGW C-17s were Baldwin 10-26E, drawing 10 locomotives, which have the same dome, bell and sandbox spacing. However the mud ring at the bottom of the firebox and therefore the top of the frame was straight on the drawing 18 locomotives, but the drawing 10 locomotive had a dip in the top of the frame, as the bottom of the firebox dropped down at the front. The drawing 10 locomotives only had 48" between the cylinder centerline and the first axle, while the drawing 18 locomotives had 54". The distance between the first and the second drivers was 39" on both drawing types, while the drawing 10 locomotives had 51" compared to 45" between the second and the third drivers for the drawing 18 locomotives. The distance between the third and the fourth drivers is 51" for the drawing 10 and 46" drawing 18 locomotives. Both types have the main rod connecting to the third axle.
The D&RGW C-19s were built to Baldwin 10-26E, drawing 2 and they have quite a few differences, including main rod to the second driver, a difference in driver spacing, and a difference in the dome, bell, and sandbox spacing. I had thought about turning a Bachmann Fn3 C-19 into RGS #42, but besides new frames, several other changes would be needed.
The Silverton Northern #4 had an upper and a lower front frame bars to the front end beam, whereas the #3 and the D&RGW C-18s only had the upper frame bar. This may be why photos on plowing snow show SN #4 behind the plow. The double frame bars would have helped to prevent bending or breaking the front frame bars.
