Not the best of the old school mags - that's Club International, of course - but certainly a cut above Escort and Fiesta.  Razzle though grim, had its own charms.

Classiest was Mayfair IMO. You’re probably right that if going downmarket from there it was probably best to go for sthg like Razzle with a focus on improbably buxom serving-wenches in M&S skimpies

Am I alone in wondering why the UK arm of Ford Motor Company chose to name two of its small car offerings after grot mags?

To be fair, they did have a Spanish / Italian naming theme going on, so Fiesta is excusable, and not out of place.

I’m unable to explain Escort. 

at the bottom end of the market, Firsta and Escort (the magazines) were just grime ubbish, but Razzle, while just as cheap, was somehow both more humorous and, IIRC, a bit hornier 

Grime is why they were/are good.  I still occasionally buy a Razzle at the petrol station and still get the same buzz.