Lighting, Light Fixtures, Ceiling and Exhaust Fans - rewiring a vornado air circulator fan

Hello,
I have an old Vornado Air Circulator, made around 1950.
The device was working fine last summer and I was impressed with the circulating capacity. It is a very powerful fan. But for one, the thing started to squeak very loudly. This had something to do with the propellor shaft I assume. However, I couldn't get the assembly disassembled - and even if I succeeded, I don't know what I could have done. The construction is very solid.
Moreover, the electrical became intermittent. I notice little sparks within the cylindrical casing and when I removed the case and the accumulated grime, the wiring seemed very iffy. Someone else had been inside and a lot of wires were shabbily insulated with cheap tape. Can you tell me my options to restore this fine instrument. I have some electrical savvy and even researched the patent on the thing to get an accurate schematic. But I need some practical assistance.

Thank you for your assistance.

To just have it work:
Make diagrams, and take photos.

I'd get modern 105 degree C wire (in historic colors perhaps), and use 105 degree shrink tube to seal the connections in the moter and elsewhere.