Thank you, all, for your help. I massively appreciate it (being new to Lexus ownership!)
I've established it's got the Mark Levinson sound system (someone has put 'BOSE' beneath the hazard lights for some reason); and the service history suggests that it had its last spark plugs change at around 140K, so they've got some live in them. Its Mot history has zero advisories on it for the past 5 years. So think I've had a good buy, in spite of the high millage. I'll put some pictures up in the coming days.
Finally (and I should've asked this in my first post) is the car compatible with E10 fuel? Trying to find a definitive answer for this. Thanks for reading this