You might post on the Facebook international basenji board.. not a lot of members, but who knows.
Found R/W male Austin TX with CA tags
I saw this on the Basenji Rescue and Transport Facebook page and the person posted a couple photos of him also.
A Red and White Basenji, named Alvin, was found in Austin, TX, today, Sunday, January 15th. He came up to some people near Lamar and Hwy 183. Do you recognize him? He has a rabies' tag that goes to a clinic in California. Alvin is apparently well-trained and responds to lots of commands. The clinic that first scanned him said the microchip he has was not registered, but the people who have him said they went online and found a nationwide registry, the chip is from Home Again, and the company has left a message with the owner on file, but so far, no response.
There should be a way to verify ownership and/or vets office via the rabies tag/number.