Quoted:
Are you talking about the molding date of the plastic base plates? Strictly speaking it would have no relevance to the magazine bodies date of manufacture. (of course 99 times out of 100 it would be right, or possibly even pre date the magazine body, but I'm talking for arguments sake. It's a floor plate, not a magazine.) ;)
Perhaps, but it is the only way I know of to date magazine production, as they never date-stamped the mag bodies. They just started stamping them with the LEO restricted markings after the AWB went into effect. The magazine law in NY is a bit vague, so it is hard to say for sure what would be relevant, and what would not. If anyone can get a better answer from Sig, hopefully they will share with the rest of us.
Oh, and there is lots of good info on
Sigforum as well, for those who don't know.