Hey Spajohn, Those are known as Banjo oilers, I've seen them listed as anything from Military to Bicycle/General purpose oilers..
Very interesting...I have a few of those hanging about. Since we're here about oil, here's a mystery oil can I've had for years, don't know where it came from, but for some reason think it had to do with firearms or at least the military.
Anybody recognize this?
I never thought of keeping my empties over the years.