To belabor the point a bit, here's what's been going on with the speedo:
I took Jfry's advice and beveled the mounts. Then caulked the speedo into the coupling, put various and sundry sealers, shrink wrap, and what not in there to hopefully keep it dry, and assuage any fierce vibration.
Then, some of our good friend JB weld.
And finally, paint.
Even after two rounds of sanding, and filling pinholes, I still got this:
on the back. You'd really have to look to see it on the bike (pic shows up much worse than real life), I believe it'll keep water out. Going to call it good enough. If it really bothers me, I'll find a sticker.
