The original Mustangs sold in Europe could not be called Mustangs because the name was previously used by a truck manufacturer, although it had been out of production for over a decade.
The Mustangs carried model number designations.
The company that owned the name offered to sell the name to Ford for $100k but Ford turned down the offer...........................
That seems short sighted. $100k to them is couch change.
I believe the problem was only in Germany.
Everything I see has the reason as being too costly to retool for right hand drive, and the different safety and emissions regulations, which often vary from country to country. A range of engineering specifications from how headlights are configured to the height of a hood need to be met before a vehicle can enter a market.
Not saying that you are wrong, just that I can't verify it.
SOURCE of above, but I didn't do a straight copy & paste of all of what I wrote above.