be carefull which variety of blasting medium is used...
as far as i am aware the original finish to the hubs was done by blasting with stainless steel balls rather than a grit.. this "peened" the surface of the alloy creating a work-hardened surface on the alloy
bead/grit blasting will produce a dull highly absorbant surface to the alloy of the hub that will just discolour and look shoite in no time
if you find someone that does it... let me know
i want mine doing on the g/s
hm