There was a posting a while back by someone that had five 15" splitters made into the 16" rims, at Stocktons. He didn't like the result because of the setback, which was 3 1/2" and sounded perfect to me. I have read of others getting the 15" done the same and had been very happy.
You need to be careful to get the correct result. As they cut the center down to get the correct diameter, the setback changes because of the curve. You would really want to make sure that you can get the correct setback out of the 17s when this is done.
