The markings on early '03A4 rifles were partially obscured by the scope mount base, but they were shortly relocated to clear the scope mount, and they were still marked '03A3. If yours is marked '03A4 then Bubba did do that, or you need better glasses. If your grandfather's rifle is marked '03A1, then someone added the A1 marking. I would be pleased for you to prove me to be incorrect. How about posting photos of the two rifles you have referenced? I'm all but certain that everyone would enjoy expanding their knowledge base.