Vintage Sterling Silver USAF Vietnam War Era F

Vintage Sterling Sterling Balfour USAF Vietnam War Era 1970s F-105 Thunderchief Tack Lapel Pin, the pin weighs approximately 1.0 Gram (without backs) and it's size is approximately 1/2" x 3/8". The pin was made the the L. G. Balfour Company and the the pin is stamped Sterling on the back and has the Balfour maker mark stamp as well. My father has several of these in his old collection of his Vietnam service time items when he served over there and I have never seen one like this anywhere online so they seem pretty rare. These pins are in very good vintage condition for being over 40 years old and I do not believe my dad ever worn them, and sale includes pin, pin back and original storage box with green foam. The item shows light wear and each one has tarnish present which can be removed with good cleaning if you so desire. The green foam in each the box protecting the pin is deteriorating due to age and is falling apart & sticking to the pins. The pins will require cleaning/polish