I've got one or two red imps in storage, can't recall if they're 700's or 700c's. Now I'm hoping I've got a C to compare with. Never paid attention to the C, now I'm wondering what it signified... Maybe cordovan vs standard shell?
edit: Going through my emails, I've purchased 4 700c's between 2010 and 2020 and one 700 and one that I can't tell from the thumbnail in the email... Also sold at least two of the 700c's. Still, most likely what I've got in storage are C's. Fingers crossed.
(Checked some old photos and one is for sure a base-700, hoping there's a C in there too, but I did sell a C about a year ago, so that may have been the one I'm thinking of).
I don't think any are Cordovan. They are all Shell though I believe.
The 700c's seem like they went through a roller to compress and harden the top surface.
They behave identical in use, same thickness, same material just a slightly different treatment.