To my knowledge, there was an authorized dealer in Monaco that offered them & the car did turn up at the Top Marques show in 2006.
But as far as any that actually made their way into public hands, I don't think there were any; just the S7Rs run by privateers. I've read that the car itself may never have actually been technically legal to sell in Europe.
As far as the Terminators, I can't say 100% positive, but I wouldn't be surprised if a few made their way over through the US military or other importers.
The Terminators were never imported officially by Ford. You could only buy them through the American car dealers we have here and subsequently they were priced at around £35k ($50k at todays prices) when new.
With regards to numbers there are very few over in Blighty, I'd guess between 20-25 models and only true Mustang fans know what they are. An example of how highly respected they are is that the chairman of the Mustang Owners Club Of Great Britain owns a dark grey Terminator with a few little mods to boost the power. He's had the car for years and I think he still has it.
We were fortunate enough to have one back in 2010 and we loved it, my dad owned an '01 Bullitt before switching and straight away he could tell the difference in handling and road holding as well as power. My mum actually drove it around our town without the traction control on and absolutley smoked a guy driving an M3. The one we had had a smaller supercharger pulley and when you floored it the boost gauge on the dash went off the scale. Gave me the biggest grin ever! Weirdly the seats in the Cobra were THE comfiest ones I've ever sat in alongside the ones in the Bullitt. Unfortunately we had to sell it a year later for family reasons. Only now with hindsight we didn't need to and slightly regret it. There are some other models knocking around Europe, we went to a European SVT meet a few years ago and videos were made about the show.