You got it - that's the standard & I even re-measured to make sure - these are a 52mm hole with a 4mm collar all the way around for a even 60mm area for each gauge.
I'll make a priority of getting pics up, but as I understand it Adrian is re-tooling the process - so what comes out may be an even nicer constructed piece than I picture, and what I have is no slouch on it's own!
I'm trying to source some fairly elastic alcantara like fabric to cover mine - just to further match the interior - if I find a good product that matches the grey leather/dash/wheel, I'll post up what it is & sourcing etc - if there's anybody who cares to go further than just the paint route.
Thanks Linus - Can you see about an oak/tan fabric aswell?