Students at St Cuthbert's RC Primary School in Edinburgh wrote to Paul's office asking if he could wish their departing custodian a happy retirement.
The typed and hand-signed letter from the Beatles star reads: "The children of St Cuthbert's have sent me lots of letters to tell me how much they like you so I reckon you must be quite a good guy.
"I want to wish you all the very best on your retirement and remember keep rockin'!"
... Andy Cairns, who turned 65 this week, told Press Association Scotland: "I'm a big Beatles fan. The kids had sent letters to his office and he responded, which was amazing.
"I'm just overwhelmed. I thought I was in a dream at first. Words can't describe it, I'm such a fan, it's just amazing."