Mr Barry said: “When John left, he was that much of a nuisance and a bully and that much of a poor student the school staff didn’t want to acknowledge that he ever went to the school and removed any trace of him.
“He was never spoken about, he was never acknowledged through Beatlemania.
“Apparently fans would come to the school gates and just be sent away because the school didn’t want any connection to him.
“They didn’t want to idolise him and for students to think you can prat about and be a bit of a bully and still be successful.”
Mr Barry said today’s pupils were well aware they were walking down the same corridors as Lennon.
He said: “At the start of the year we always have new students coming in who are so happy to tell us ‘this is where John Lennon went to school’ and we say ‘We know, we work here!'”
The desk and ledger, along with old school signs and uniforms from the Beatle’s schooldays, can be seen at the museum on Mathew Street.