Ok, as mentioned last night, took the carb body with drawing to an EDM shop today and they performed their magic.
The attached photos show a 6mm wide channel that is 0.8mm deep, wire eroded out of the wear areas. A quick and pain free exercise.
If I was to do again, I would get him to take back the front face of the carb body by maybe 0.2mm to get rid of the majority of the wear present on it.
A new throttle plate could be made that is thicker by the same value to compensate and keep the clearances the same.
Next step is to cut the insert strips and these will be made with 0.8mm stainless steel. They will be fettled to a good press fit and bonded into place. Any unevenness will be made good with light stoning to leave a flat surface.
It'll be a week or 2, maybe into Christmas before I get this completed and tested, but I'll report back as I make progress.
For anyone without a worn carb I would strongly urge to replace the wheels with ones that are 1mm wider and from a softer material. If there was enough volume I'd think these would become only a couple of quid each. The Keihin item is £8 in the UK. These could then be replaced every year and there will be no future issue with carb wear. I'll get some made and let you all have a look and think.
If I'm missing anything, please shout before I go flat in 6th over a cliff edge
Cheers
Gavin
P.S. Photos to follow, looks like I have to upload them first ......gggrrrrrrr