Well, CDY serial numbers were coming out in February 2000, and CEA guns were seen in March of that same year. So all things being equal, that suggests your gun is in that time frame. But because the company doesn't always run serial numbers in strict alphabetical or numerical order, and sometimes reserves or assigns three-letter prefixes for special models or specific runs out of the "normal" production sequence, I would hesitate to claim that date for your gun.
I looked in the model summary in the Standard Catalog of Smith & Wesson, but I didn't see a 629-5 model listed with a three inch barrel. I did, however, see a product code 106310 (dash number not specified) with a three inch barrel, unfluted cylinder, and finger-grooved round butt stocks. If I understand the listing, this model came out in 1985, well before the -5 revisions. So I'm not sure I know what's going on there.
That obviously doesn't answer your questions. Sorry. Perhaps somebody with a Lew Horton 629 can help you with this.