RE: 1970's Sears Dual Motion Sander that gave up the ghost recently - major rattling noises and then only a hum when switched on.

After splitting the case I don't see anything obviously worn out besides the uppermost bronze bushing. That one is very sloppy and the lower one seems tight. The brushes are about half worn out.

Could that sloppy bushing be the reason for the tool to stop working? If so, where might I find the part?

Thank you.