Why do I get the feeling that we've been over your idea before?
(Go ahead, make my day!)
Hey, as long as the baseplate is replaceable, it's all good!
The o-ring is top notch. I'll be using a 1/16 silicone o-ring, and if I keep the groove smooth, everything should stay sealed very nicely. Just remember to let the o-ring sit
in the middle of the groove (or equivalent, if not round), and everything will be fine.