I have two with bumpy shells too, but in my case it's because they were raised on the dry side as babies. I've since learned that baby tortoises need quite a bit of humidity. And the moisture in their environment makes the shells grow smooth.
In your case, since he's also a bit big for his age, it might be a combination of too much food and not enough moisture. As long as metabolic bone disease isn't accompanied by the bumpy shell, it's purely cosmetic. I doubt your new baby suffers from MBD. Just be sure to offer calcium-rich foods or a calcium supplement several times a week. I think the opuntia cactus is calcium-rich.
In your case, since he's also a bit big for his age, it might be a combination of too much food and not enough moisture. As long as metabolic bone disease isn't accompanied by the bumpy shell, it's purely cosmetic. I doubt your new baby suffers from MBD. Just be sure to offer calcium-rich foods or a calcium supplement several times a week. I think the opuntia cactus is calcium-rich.