I bought a blast cabinet at Harbor Freight and out of curiosity I inquired the same at a local supplier when I went to get blast media. They said use finer and finer grits of aluminum oxide media and finish with ground walnut shell. Then go to the buffing wheel w/polishing compounds. I haven't tried this yet, but I bought the materials and waiting to try it. I intented to leave the cast finish but give it a bright sparkling appearance and do a mirror polish only on the flat machine surfaces. I've got another car to finish body and interior first tho so lmk if you get to try it before I do and post some pics.
Phil D.
Phil D.