It's a keyboard called a Clavioline on its oboe setting. Early Motown records had one, mostly played by Miss Ray (Berry Gordy's wife) - witness 'I Want A Guy' by The Supremes: Also, (obviously), 'Telstar'.
Those are Paul and his brothers; Paul (sitting), Faul (standing to the left), and Maul (sitting, right). I'm pretty sure that LiaramI Fullofit talked about this outing in his book 'Barcleona! The story of Carnival Of Sound'. This was when Paul and John rode around in a boat in NY and talked about forming Peach records.
There was an interview with the guy in the background on the Abbey Road cover. (He is just above John's head.) The guy had no clue who they were. First of all, how did they even track down some random guy in the background for an interview, especially after the fact? And secondly, how could anyone not know they were the Beatles? If he only knew what he was witnessing...
Like most What If? questions, there's so much you'd have to transplant that may or may not stick, and you'd have to work out everything all over again and the whole thing would ride on unknowable conjecture ("Would Ringo have had a different nickname due to Mancunian senses of humour?"). Personally, I therefore don't care, not to be rude....
If from Manchester, the Beatles would have been either Herman's Hermits or Freddie and the Dreamers. Their big hit would have been "Do the Pinwheel Twist"
It’s repetitive, lacks excitement, and goes nowhere. Oh, and it’s boring. The fact that it exists at all is the most interesting thing about it.