UPDATE
A couple of folk who I know are extremely particular about their cars spoke very highly of Chris at BMV Cosmetic Car Repairs, who are a local company near me. Hence I contacted BMV via their website, which has the facility for enquirers to upload photos of the damage & Chris responded promptly with a very reasonable quote. I then booked the car in for today, which was BMV’s earliest available slot (a 4 week wait - in my opinion it was a good sign that they’re busy).
The scratch was repaired on my driveway this morning & I’m pleased to say that Chris has done a really cracking job, I honestly can’t tell that any paint damage was ever there & it literally is just as good as new both in terms of colour match & finish.
I’d definitely use BMV again (although I hope that I never have to!)
Thanks anyway for your recommendation Noel, which was appreciated even though I then used a different repairer to the one you’d suggested.