TOPIC:

Did you mean 0.2 mm or 2.0mm for the idle adjust gap? But regardless, that would mean it’s not doing anything right? Think I need to reset it all again and start again from an approx static balance. And just a paper thin gap on the fast idle cam?

Did manage to go out on it today though, about 60 miles and was a lovely ride, at least!

2. 0 mm

".......got the balancers pretty much all the way out and still around 9 inHg, at best with some going above 10" 

 There is no way I can think of where you can have the (Sync) adjusters on the linkage rods all the way out and still have 9" to 10" HG !
The Only conclusion I can come to is you have assembled the link-rods incorrectly.
 #58 is installed upside down or one of the 2  #55 is installed upside down. 
The "pin-end" of #58 fits into the hole in the bottom of the rod.
The "pin-ends" of #58 fit into the spring (#5)
 
This adjuster/nut are in the correct postion/height relative to the rod..
 

I should clarify, not an issue of the adjustment, I could tighten them more to get there, but the engine shuts off, perhaps my gauge is wrong and the values are off? Or there's something else wrong.