Pryne Blo-Fan circa 1959

[madrivermaz]

I'm asking for help on how take it out of my kitchen ceiling. It works, but hasn't been used for at least 20 years.

There seems to be some sort of spring-loaded cap in the center, but I can only pry it down a little, but it rotates completely around.

Help if you can.

Thanks in advance.

[Obi-Wan Canopy]

Center cap unscrews by rotating counter clockwise.