1950s Diehl 16in oscillator arm question

[Jen Brown]

Hello all,

I'm brand new to vintage fans and the community but looking for some advice. I found the below pictured fan in my father's workshop after he passed suddenly a few months ago. He was mechanically inclined and always restoring old appliances. I wanted to clean this fan up in hopes of using it in his honor.  After some elbow grease it came out looking pretty good and runs nice and quiet. However it only oscillates to one side then stops and does not return.

After some online research it appears its missing its cone cap and oscillator arm (forgive me if I'm not using the right terms). I can live without the cap but I assume the arm is the reason it isn't returning? My first question is if anyone might know of where I could find a replacement of this part?

I also read that if the back gets overly hot while running itd be a good idea to clean out the grease and replace it. Does anyone have a fan like this with possible pictures to show the easiest way to do that? I could just start taking things apart blind but any advice would be greatly appreciated. Again please forgive my ignorance I'm brand new to this but excited to learn!