I have already scripted a Mersey Beat film and have been trying to get it made since the early 90s. It's a sort of British American Graffiti, about a weekend in Liverpool in 1961. I also developed a Mersey Beat TV series, had Britain's top TV screenwriter, whose series 'Heartbeat' was No. 1 in Britain, had the film company who produced the movie 'Gregory's Girl' ready to produce it and we presented it to the BBC. They held on to it for three years, then suddenly rejected it, ripped off the name and used the name 'Mersey Beat' for yet another cop series, which flopped. Personally, I think it was unethical of them.
I helped Ray with researche when he wrote a script 'Working Class Hero' about a young John Lennon, which had the story end when the Beatles first appeared at the Cavern. It was probably the best rock movie script ever written. It had been commissioned by Warner. When Yoko heard about it she approached Warner and told them that if they would do a film with her instead of using Ray's script, she would give them access to film and music. They agreed, junked Ray's projected movie and produced 'Imagine.'
This is the reality of the movie and TV world.