I just picked up a minty first year Winchester 670 -105xxx- now on the hunt for non existent .225WCF brass or ammo too!
Winchester still makes 225 Win, but it is only made once or twice a year. I found they don't like to answer emails, unless it concerns a safety issue. They do answer letters. I would ask them when the next run is going to happen. You may get lucky and receive a response.