Potential red bus candidate. RML 2548 (JJD 548D)
Seems to be a good match, there maybe a few caveats there though, not sure how clear the RML2548 ID would be in the Q pic, that may just be a res issue, font size appears about right. Also the angle of the steering wheel, in the Q pic it appears completely level, however I am wondering if they are adjustable or if they are moved getting in/out of the cab - having a look at that atm.
No bar/advertising frame
White text by the step by front wheel
Something just above the panel line just above step - routemasterhire.com url
Top window handle(?) location
https://www.routemasterhire.com/gallery/wedding-bus-gallery/