Repaired scratch on rim of 2.7t sport wheel looks pretty good -- almost undetectable.
As suggested in the related FAQ on this site, I CAREFULLY sanded the scratched area until it was smooth. Then, using a tube of "Polaris Silver" touch up paint (for my old '77 Bimmer), I painstakingly painted the scratch with several coats. With each coat, I expanded the coverage extremities a bit more, feathering the edges into the surrounding still-good wheel paint. (The "Polaris Silver" was a good match with the still-good paint.)
The final result is now hard to find, even by me, the "artist." Hopefully, the repair will hold up fairly well over time. If it doesn't hold up, I may try some silver colored epoxy paint next time. (And, if time permits, I may try to post a picture of the current repair result, though I didn't take any comparison pictures BEFORE the repair.)