Interestingly or not, having worked out the spacing for the hinges they all appear to be imperial.
Maybe the hinges were designed in America? Although these here are about 20 years old, donated by my sister from when they had their kitchen done when their house was built. The hinges themselves are made in Austria. I suspect if you buy them now they are all made in China! Still that's progress. Considering they have sat in a bag in their attic for 20 years they look like new. Thanks Sis.
Because I've fitted face frames to the cupboards, you need to space the hinges off the carcass. I'm sure you can get special hinges for the job, but when I last looked in a certain well known UK diy store they had the same hinges, but with a plastic spacer. I don't have the spacer so a block of wood will do just fine.
Now I've worked out all the spacing the rest should be an "easy gig"