I need to echo everyone else here who has suggested making sure your dogs' microchips are still where you put them and working! Every year (and sometimes more often) I have the vet scan both of my boys to make sure this chip is still in the same place, active and displaying the correct ID #. I carry a dog tag on my keys that has their microchip numbers and the phone # to the company so I can immediately call and report them lost.
I heard back from the finder this morning. She says his face looks like Basenji, but his tail is long and straight, not curled. So she thinks he might be a mix. Anyway, she is going to take him in to the vet to check for a microchip, and will hold on to him for the rest of the week. If he isn't claimed, she says she will contact BRAT.