Replacement slip ring for flag pole swivel

I have an flagpole which uses plastic slip rings to keep the flag from tangling up in the breeze. Unfortunately this plastic tends to crack after a couple years of sun exposure, and while replacement slip rings are pretty cheap, it's nice to have a short-term fix that can be applied quickly. So this is that short-term fix while I wait for my replacement parts to arrive.

This part is sized for a 1" diameter flagpole's slip ring mount. The .scad source is provided in case you need different geometry.