I need 2 GE Astrodome plastic covers that cover the holes that that the PCs look out of.

If you can't find the OEM GE cover I think this should be a fairly easy part to 3D print, you just have to use something that'll stand up to outdoor use so maybe some clear PET filament or something.

Here is the spec sheet: https://products.gecurrent.com/sites/products.currentbyge.com/files/documents/document_file/lgout106-ge-powrbracket-pbp-pbs-roadway-hid-renewalparts.pdf

I don`t think the parts are still made, though.

I'll look when I get a chance !