If the Remington model system for centerfires follows the system for rimfires, the "C" designates a pistol gripped stock (which yours has). Not sure what the 14-A designates. I know that the 14R is the carbine length model of the 14, and the 141 is the late "modernized" version with a fuller stock and a longer barrel. Some of those were made post WWII.
The earliest .30 cal 14s were marked ".30-30 Remington." Apparently that confused some people so Remington changed it to .30 Remington. I imagine putting a .30-30 WCF in a Rem 14 or 81 jams it up really good!
Both your pumps are neat guns. The 14 is a remarkable machined product; it would cost a small fortune to make today.