So I might be a tad confused but after looking at the catalogs online I see they didn't change the model numbers as the 4214 model and the 4514 model snares are completely different. We both have the newer mid 70's 4214 Copeland 5 x 14 snares :)

Apparently in the early 70's the 2 line snare was either a D4514 for COS or B4514 for the COB version and they looked the same with only the 2 beads. Highlighted the differences attached . . .

Ha thanks Eric, bit confused too as the 3rd image snare has no sound hole on the front at all. I think I'll just play them and enjoy the snares for what they are!