Smiths Chronometric Conundrum

With speedos occupying the ol' mind pretty often over the last week or so, I decided to dig this out of the shed. Don't intend to use it on the Newgate's Knocker project, that's getting a "D" type...... end of story!  The speedo above has been kicking around for 25 years and more, yet it was only about 6 months ago that I noticed there was something not quite right about it.  If you look carefully it's not or at least wasn't a speedo at all. Somebody, back in the mists of time, has put a speedo mechanism in a rev counter body. Why?..................who knows now, but there it is, maybe an old Cafe Racer thing to have two matching clocks, somebody came off and messed up the original body.

So the problem is now, what to do with it, it really needs stripping and the mechanism cleaning and overhauling if it's to be used., the three options that are available seem to be;

1. Just get it cleaned internally and run it as is.
2. Restore the body, new glass and needle and just clean up the dial that's on there.
3. Turn it into a Rev-U-Lator for future use or profit

I'm angling towards the second option at the moment, but nothing's decided yet.