Question on rear isolastic fixed clearance

Could someone please tell me the fixed clearance for the non-adjustable side of the Vernier rear isolastic mount? That is, the clearance for the side which is locked in position with the small Allen grub screw? I am replacing the rubber mount and the nylon washers on my 850 Mark 1. The old PTFE washer on the fixed side was worn, so any measurements I made before dismantling would have been unreliable.

Incidentally, I found that the bore of the new isolastic rubber mount I got from Norvil was significantly larger than the old one, also a Vernier, so much so that the engine through-bolt was an excessively sloppy fit. I had to sleeve the tube so that the engine bolt is now a snug sliding fit. In all other respects, the new mounting has the same dimensions as the old one. Is this a mistake in manufacturing or did later Commandos have a larger diameter rear engine bolt?

Good question Dave. I was told by Norvil to install the rubbers centrally as normal and the locked end cap should just pull up against the rubber. That almost works but I did have to ease the rubbers towards the locked side so there was slight clearance, hardly any so when adjusted there is some on either side. I suppose you should aim for half of the total you want to run on that side so you have even gaps. I'm not sure how important it is though.
On the tube ID mine are also large, much larger than the old shim set up I was running. It's probably down to using a metric tube, easily and lower cost material maybe.

Thanks for the reply, Keith. My instinct was do as you have done but you have given me some encouragement. It took a bit of fiddling, but I reckon it's OK now. I set it to 6 thou and I will see how I go from there.

I'm doing this with the engine in the frame and the rear of the bike suspended. It's awkward but do-able!

Dave