Warrant Officer Rank Question

[aclfan]

I obtained this Warrant Officer rank on a WWII service cap piped for an enlisted transportation corps soldier. While I know that is incorrect for this rank, I am having trouble pinpointing the actual age. It looks like a W3 rank from the late 50s to 70s, but has is a pinback and the back is not marked with a manufacturer code. The manufacturer was E&H Simon Inc. and also marked Sterling. How late were pinbacks used for rank? 

 

Thanks for any help. 

[patches]

Probably a very early 1954 made one, these new WO insignia come out sometime in 1954, and it was made juust before the new hallmark codes come out, which was in 1954. But on the other hand it seems  E&H Simon Inc.had no hallmark code.