I still want to see a pic of the engine, before I'm convinced

Interesting topic though, badged as a 16v would have meant that someone had placed a bin full of badges at the end of the 8v production line, and left the factory, after being inspected! then delivered to the dealer, and missed on the PDI. I would have thought that misbuilds would be more likely to be things like, the wrong fabric on seats, wrong tint of glass etc, the sort of stuff that is specified on the build code sticker in the boot
Imagine ordering a Ford Sierra GL, and you take delivery of a car badged as a Cosworth Sierra

For me, the most likely scenario is that somehow the car was rebadged at the dealer, maybe the original owners bought a cancelled order, where someone wanted it badged as a 16V... we'll never know
Thom