By older, I mean what many would call "vintage". I would imagine an old ROV would work great as a ROP! If you've modded an older light, please post a pic.
I made a rop out of a ever ready bullet nose flashlight,worked great,I also put a mag 2d led in one,It needed a serious diffuser to look decent.It is fun putting new life into old lights.Be sure to find lights that DO NOT use screw in bases.They are a lot harder to work with.