Beogram 4002: DC Motor Restoration

I recently received a Beogram 4002 DC motor for restoration from Missouri. This shows the motor as received:

I disassembled the motor to get the bearings out for oil infusion:

The bearings are the two small donuts on the black pad up front.

I immersed them in motor oil and pulled a vacuum. Immediately bubbling started:

This indicated that the vacuum drew the air from the porous bearing material, which makes room for the inter diffusion of oil. After about 48 hours the bubbling stopped and I extracted the bearings:

Then I re-assembled the motor and installed it in one of my Beograms for a RPM stability measurement with the BeoloverRPM device, which allows logging the RPM for extended periods of time:

This shows the result of a ~24 hrs run:

This is pretty much as good as it gets for Beogram DC motors. This motor is ready for duty again.