I have a hunter ceiling fan with a light fixture. The plastic mounting fitting for the light to the fan is cracked beyond repair. It has an embossed name "Robbins Myers' with the number 83153. Where can I purchase another one of these. The fan is about 21 years old

I am pretty sure the part you are referring to is not replaceable. EMail me a picture and I will confirm.

If it isn't, I would be interested in the fan for parts. If it IS replaceable, I will direct you to the correct part to ask for from Hunter.

Pretty sure your fan is older than 21 years. Robbins & Myers owned Hunter in the 70s