Get some Dupli-Color code number T488 GMC truck and suv pewter and
their clear lacquer. If it is smooth enough for your tastes dust it on
with a mask to keep it only in the damaged part. It should be clean
and etched if possible. Do not put masking tape on to control the area
to be covered, use a mask about 1/4 inch above the surface so it will
not leave an edge. Remember, dust it on with the spray nozzle about
12" or more above the surface being painted. You can apply a number of
coats and wet sand it out smooth with 400/600 paper. Note, this will
match the Z06 C5 wheels and I was guessing that it is close enough to
do the C6 painted wheels, if not try another color until it is to your
liking. When you're done put on a wet coat of clear.

You can also fix the rim by putting a bead of epoxy on the aluminum
and sanding it to contour and the paint will hold better than it will
on the aluminum. Use a flat file to keep the rim close to the same
shape. I've done it so I know it works, don't ask.

Try emailing Bob at parts@fichtnerchevrolet.com for a bettter price on
GM parts.  Or Gene at www.gmpartshouse.com

For salvagers, try
http://www.corvettesalvage.com/
http://www.justcorvettes.com/
http://www.contemporarycorvette.com/

http://forums.corvetteforum.com/zeroforum?id=115
Keep looking.  There are a lot of good people there.