I have a WWI vintage "Sweetheart's Brooch" to the Motor Machine Gun Regiment for sale for $40, plus $2.75 first class shipping. I don't know much more than it is gilt, and has Vickers Machine Guns featured on it. It measures 1 1/4"H x 1 1/8"W. Here is a photo:
I accept PayPal, as well as checks and money orders. If you are an Ohio resident, I must collect your local area sales tax.