I do see a reason to remove them during head rebuilds in order to properly clean the heads. Through customer's bikes and my own, I have dealt with a lot of these for a lot of miles. They need nothing to stay in place but a aluminum crush washer, anti-seize, and proper torquing. Proper torque? Look up what the sump drain plug gets. I don't believe Euro models had the system at least up til '85. BMW has prided itself on being 'green' for years now. For instance, no one forced BMW into putting cats on oilheads but cats they do have. I don't think anyone forced BMW to use air pumps on their bikes. Not at first anyway but I don't know for sure. Ca. did force them into using their anti-evap system on their gas tanks and engines. Complain about emission regulations? Go live in Peking!