I had a similar thing with a 2.8i capri that I had. I bought it off a pal of mine in 2012 and sold it in 2018. It was a 1983 but it had most of the extras/differences of a 2.8i special model that were released the following year 1984. Half leather Recaro. Five speed box, lsd and the flat faced 13” wheels which eventually got changed to the Brooklands 15” rims. Someone could well have retro fitted the special parts to the car but like yourself it had an unusual vin number/vin plate so it could have well had been a special order for someone at Ford, a director or member of the development team etc.If the car has an unusual vin it could well mean it was a special order of some kind.

I believe there was an automatic sapphire cos that came from factory so when ordering a car new it’s possible to spec it to how you want it. When the sapphire changed from 2wd to 4x4 I would have imagined that some of the later 2wd’s had the optional extra choice of the leather but I could be wrong. I saw a mk3 cortina on a motoring show once and iirc that had a 3 litre Essex v6 fitted from factory. That would have been a special order no doubt.