Any idea on the age of these jump wings

[PMAN12094]

I'm thinking Vietnam era I believe they were subdued at one time but the finish has worn off 

[Tonomachi]

This could go back to the SVN War era as it has what looks like genuine wear on the front and back.  It has an antique silver finish over some sort of brass alloy base metal.  It is a NS Meyer style paratrooper wing.  I have seen so many variants of this style wing over the years with the same front but different rear (solid backs, partial hollow back & full hollow backs) in pin back, screw back and clutch back.  Some are hallmarked NS Meyer in pin back or clutch back, just STERLING or no hallmark at all like your piece.  You have to be careful with this style wing as someone has been producing copies of this style wing hallmarked NS Meyer over a number of years.  Below are photos of a pin back version, screw back version, clutch back version and the latest poorly made wing mounted on a NS Meyer card.