You are probably right. I've never seen a C-4, but read mentions of it such as this:
https://www.garagejournal.com/forum/showthread.php?t=216573
"As far as price, compare it to a new 1745 or 1765 andprice the new parts. If you come in at 50% or less of new, I say it's not a bad deal. For reference, in my part of Oklahoma, I paid $50 for a 1755 that needed new jaws and was missing the cap in the back. But I also paid $40 for a
C4 2 weeks later. Put an ad on CL looking for a US made vise. You'd be surprised what you'll come up with."
Maybe the OP was talking about a Reed 4C ??