After spending most off the last few weeks working on my other bikes I've had chance to look at the clocks/trip meter of my SR.
Thanks guys for the documents on servicing and the tip of some rubber strap wenches
I've pulled it apart, still wasn't easy.
I took some pix to help illustrate the issue.
the problem was two fold, first the shaft of the release cog was bent. But also the mounting block that bolts to the sideworkings was loose and just needed the screw tightening.
The only problem on reasembling the clock I couldn't get the bezel to seat and if you look at the pix you can see why someone it its passed, has used a screwdriver to prize it off
so a new one is on order