Mark - R. J. Decristoforo was the author of
POWER TOOL WOODWORKING FOR EVERYONE. In the first edition he used a 10ER. Note the name on his handsome shop coat below...
"Cris" at work on the Shopsmith
Here's an interesting tidbit on the 10ER history:
"The machines made at the San Francisco plant had an "R" in front of the serial number and those at the Cleveland plant had an "E" (for east). The plants evidently kept track so that no numbers were duplicated. If they had kept that pattern up it would have helped a bunch but after serial numbers get to 60000 range they quit putting the prefix on them so you can't tell what plant they were made in. It looks like, annually, production averaged around 20,000."
(quoted from this website:
http://www.woodworkinghistory.com/document_11.htm)
Maybe somebody messed up and put a "C" for Cleveland?