That is not a date. It is an integral identifier component of the Federal Stock Number format in use from 1934 to 1952. I'll be more explicit and more declarative than I have been prior. Your pliers are surplus, very likely military, very likely repacked for long term storage, probably by the Ordnance Dept, and probably just after the war or in the very early 1950's. Without ANY shred of doubt. See attachment, which is an excerpt from a 1944 manual. I'm not telling you what to do with them. But they have a value well beyond a run of the mill pair of 6" Utica or Schollhorn parallel jaw side-cutters with WWII collectors. As I alluded to upthread, WWII tool guys go nuts for cosmo and packaging that is proven wartime. I know a colleague in Australia with a G-61 Emergency Repair Truck who would love to have them for one of the armorer's boxes that went in the back. EDIT: Not to talk you out of them. Just to give you more context for what you have and the collector's environment.