I've never seen a gray stock factory installed on an Accumark. Black with flecks yes but not gray with flecks. That and the other features I mentioned in the beginning suggest ULW to me.
Then again, better/larger photos with a barrel diameter measurement would tell the tale.
Not only the bolt handle and the overall weight,and muzzle diameter say its an ultralight but i called weatherby and had them verify it via serial number.