Recently picked up a mid century modern molded plywood chair by Brunswick to use as a desk chair. Here's a photo of the chair

Love it except for the fact that it's missing one of the feet which makes it ever so slightly unstable. Using it on carpet so it's not too bad but would like to fix it nonetheless.

Here's what a good foot looks like. There's a circular metal piece in the middle that allows the plastic foot to float a bit (kinda like a ball and socket joint).

Here's the busted foot. The plastic bit broke off leaving just the metal piece:

I don't know:
(1) where to get a replacement plastic foot
(2) how the metal piece can be removed to install new plastic foot of if this can even be done

Any thoughts?