Cant help with the wheels (having not refurbished one).
The wheel center caps can be refurbished with new badges quite easy.
Badges are readily available on ebay, but get a set from one of the more reputable MG suppliers on there.
I got these wheel cap badges
Which look good on black wheels, with the caps also painted black.
Gently heat up the wheel center (after removing from the wheel) with a hot air gun, or just sit it on a hot radiator for a short time. This will soften the glue.
With a very small screw-driver, or a knife blade you can pries away the old badge.
Clean up the center cap and remove all old glue with meths or similar.
Paint them (I painted mine black) and stick new badges on when paint dry.
About 1 hour work (plus paint drying time) and makes a big improvement on looks.