Aircooled VW South Africa

I am buffing my puma's original magnesium rims to get the sparkle back. The centre of the mag rim is still coarse / rough due to the original sand casting. I dont foresee buffing out all the roughness. I have had some good results using a wire brush on a handheld drill but due to the fact that the magnesium is so soft you easily buff circular marks into the rim. I used a standard wire brush bought at game. Any other ideas or suggestions?

On the edge of the rim I used 400 and then 1200 sandpaper after which I used braso metal polish. I was told to use autosol... will still try that. The finish I got is quite shiny but due to corrosion there is still some pitmarks left in the rim even when fully shiny and buffed up. I suppose I can put it on a lathe and take off a mill or so but the structural integrity of the rim might be jeopardised.

Any comments from any guru out there?

If I remember chemistry properly (unlikely) then the best use for anything magnesium is to set it alight.

On a more serious note I do remember reading that old magnesium alloy wheels tend to develop hairline cracks over the years so it's probably work having a very close look whilst you clean them. Glass bead blasting should be gentle enough to get all the grot off, then steel wool and brasso or sliver poish.