Incidentally, until much later, Ford worked to US standards in the US, and to Metric in its UK and German factories. When the company decided to build its first "world car" (long before the Mondeo) which would be built in all its worldwide factories, the company decided to change its US factories to Metric standards
Indeed. There was a time (late 70s/early 80s?) when Ford sold cars in the UK with metric, imperial and US fasteners. Fortunately, most of the UK/US stuff was just about interchangeable as I recall (Whitworth and UNC, or was that UNF? Too long ago now) The wonders of threadology!
What the Scottish lads were used to was "fettling to fit", while the standard practice at the Ruhr factory was to reject any part that needed such "fettling" and get a replacement, while also reporting the discrepancy for corrective action further up the supply chain.
Of course, no place on the production line for fettling, but if you want to attain performance beyond the capabilities of the non-fettling opposition then fettling is an absolute requirement.