I pulled the motor, stripped it and cleaned it last night at the space. I have left it laid out on the bench for others to have a look and weigh in on the diagnosis.
I don't think it's the bearings (at least not in the motor), they feel ok and there's no evidence of the rotor striking the stator.
I also inspected the switch assembly on the press and it seems fine.
The only thing that I can see might be the issue is the starter cut out contactor looks a quite burnt (more than normal for it's age, who knows?) So possibly the starter cap might be internally shorted. I didn't have a meter on me to check it at the time, but it will be the next task.