Long answer: Not terribly long after my last post I was able to speak directly with David Coy. The place he gets the wheels from (they are not made 'in house' at Coys) is swamped with orders for 17, 18, and 20 inch wheels and there is not much demand for 15" so he is having a hard time convincing the guy he should set up for another run of 15". He offered to send me another color in 15inch to run 'in the meantime' until the new batch comes in. Not really wanting to go through the hassle of mounting and balancing an interim set of wheels (not to mention return shipping), I declined.
Fast-forward to a couple weeks ago: I got a message saying that they are being made. I hope that's the case. I guess I'll believe it when they're in my hot little hands.