The shading is intact and the motor starts and runs well now it is clean.

I have disassembled it and hope to post some more photos tomorrow.

The bearings are plain hardened steed or white metal.
They are neither brass nor bronze.

The outer boss is made of light alloy casting and taper cup shaped.

A sheet metal (steel) rose in the bottom of the cup holds the plain bearing in its centre.
A second rose the other way up is pressed down to lock the first rose in place.

The boss does not contain any oilways or oil points.
These would be pointless anyway since the oil the boss is not liquid tight and any oil would just spew out.

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There are various porous metals used for bearings - not all are bronze colour.

Since you have it apart, you can soak the bearings in oil - some people heat the oil so any air in the porous metal expands and escapes - when it cools down again, the oil is drawn into the voids in the porous metal.

 

Thanks, shortbus, do you mean fix one of these to the oven wall?

No, just replace the bushings with a sealed bearing. Then they won't dry out or be affected with any oven gases. Wouldn't the fan being on keep the gases out of the motor area? Or do you run it without the fan some time?