Talking about the Mod A and M got me wondering if there are variations in the Model C.
Here are 2 variations of the New Departure Model C, hub on bike has a machined fit, internal cap end, this looks like an earlier hub, it's shown on the link you posted early in the thread to a 1927 Mod C catalog.
The loose wheel picture is from a 1933 bicycle, regular dust cup end. Both hubs are in nickle and have the oil port with dust cap.
Question followers:
Did the Model C change during it's production run (when), or did 2 versions run simultaneously ?
.