I do like your idea of fixing it so if you have some more time to spare I made a short movie and uploaded it here:
Straight afterwards it stopped spinning up all together!
So I took it apart and noticed some movement in the motor spindle which has a metal gear at the end. Where this engages with the drive belt (a plastic gear which has even more movement c. 2.5mm) I noticed that there’s some black powder, perhaps residue from excessive wear due to lateral movement so I packed it out with a Chinese coin but as it no longer works I’m not sure where to start with replacement part(s). Perhaps it’s going to be a bit like triggers broom! Anyway, photos attached of the inside for reference, I’m really interested to hear your thoughts on this one.