A fellow I ran into who has a stack of callsign books looked up this information for me. I think it's important to maintain the hobby's history. Very interesting stuff, indeed.

K7CCC has a very short history. It was first assigned some time in
1958 (not in the Spring 58 book, but listed in the Winter 58 book)
to Wharton Murray of Salt Lake City.

As I had said, the 7th district
was one of the last to get into the Ks. Mr. Murray held the call at
least through Winter 1960, but he's not listed at all in the Fall 62
book. Unfortunately, I can't tell what happened to him (SK, moved,
etc) unless I get more books in between those two, as those kind
of notes were only published for one issue.

I can find no record of anyone else ever holding the call sign, at
least into 1995. It looks like the 7th district never reissued the K
1x3s, so unless someone else held it for a short time under the
current vanity program, you are the second K7CCC.

I hit the FCC's ULS site and found no record of a transaction with this call, and the DB they have seems to run back to 1995, with a few '94 actions. FWIW, I was initially licensed as KD7MPD.