I've only ever seen the CLC s/n prefix used on the 170170. I think it was reserved for just that one variation. It was an "out-of-time" prefix, so it doesn't follow the normal alphabetical and chronological date sequence.
I've seen them in their box with the date code, and those 170170 PowerPorts shipped in.....
January of 2000.
__________________
~ S&W aficionado in training ~
|