"I will always be proud and happy to have known and worked with this incredible Scouser!"
But he stressed that they were "reasonably well adjusted to fame"
"I needed to see proof"
McCartney described the period he spent recording at home as "rockdown"
"We had certainly got our friendship back, which was a great blessing for me"
Fans can also look forward to watching Macca's 2018 Cavern Club show in full.
The donations are to help raise money for youth music education programs affected by the coronavirus
"Sometimes I'm on autopilot"
"It makes me happy to have shared all that with him"
The 40-year wait for the completion of the 'McCartney' solo album trilogy will have to go on for another week