bushing ID is appx 0.436" - 0.437". i could only access the outer ones for a measurement with my dial calipers, not the inners. bushing flange thickness is appx 0.11" - 0.12", flange diameter is appx 1.26" - 1.27", some variance.
eBay item #231955415631. auction ends 3 June 2016.
This looks like a polishing project that someone started and didn't finish. Someone who knows what their doing when it comes to polishing aluminum can make this cover look really nice.