Question of the day!

I've got a few of these lights shown in the pic below...Had them for a while now and plan to use one on my Panhead...I've always wondered what they came off of or what they were used for? I've researched a bit, but really don't have much to go on...If ANYONE who checks this blog out happens to know what they were originally on or used for, please let me know via email...I'd greatly appreciate it because they remain a mystery! haha...Whoever happens to know and can provide me with the info, I'll gladly send a handful of stickers and a Hold-Fast T-shirt as soon as I have them ready...Thanks in advance!