UNKNOWN Sterling WWI WWII or Earlier Hat Pin Insignia Rank Cap Badge

Description

UNKNOWN origin or purpose
. I have listed these items as WWI or WWII, but they may be older.
Hallmark "STERLING" (partially worn away), the hallmark is incised and not raised. These pins were part of a large military uniform and insignia collection purchased at an estate auction in Boston. They are a matching pair and exactly the same length (see photos for size information). The point ends are extremely sharp and the "shaft" edges are blunt. The "shaft" is rigid and the "bulb" appears to have been painted black at one time, most of the paint has worn away. If you happen to know what these pins are, I am interested, so please fill me in. I have researched without any luck in finding similar items or an item description. I thought possibly this may be a fastener of some sort for a military head cover, for a plume or turban ... etc.
Please take a minute to check other items I am selling and I will be happy to calculate combined shipping.
When purchasing multiple items, will combine shipping for lower average rate.
THE PHOTOS IN THIS LISTING ARE OF THE ACTUAL ITEM AND ARE NOT STOCK PHOTOS
COMBINED SHIPPING INSTRUCTIONS
I combine shipping and handling. The first item is 3.95 (unless otherwise stated) and every additional item is 50 cents. Also, if you purchase or more of items at one time at the listed price, shipping is FREE.