Glock23dude-I saw this request on the other site. It's not that easy. Mark 2's have been in production since 1942. Of the ones you want prices on Camillus produced them from 42' until they shut down a few years ago. It would depend on markings, finish on the metal, color of leather, type of scabbards. Conetta -post Korea, & Vietnam. Ontario are relatively current. MSI-are a mystery, but considered fairly current. You say all have blued blades, that won't cut it. Only certain companies in WW2 produced them with blue blades. We need photos, to check all of the above, plus condition. I suggest do some research, it's pretty interesting stuff. Good Luck! SKIP