Anybody ever seen these before?

This is an oil filler tube w/ cap that came off of a 318 4 dr Valiant police car. that's right, a Valiant police car! It twists on the valve cover where the standard oil cap normally does but it acts as a filler tube. I know they also usedthem onlater dodge trucks as well. they look kind of cool when you have two of them on your engine. just wondering if anyone has come across these before?