Thanks, henpecked! I'm always appreciative of your knowledge and experience!
And yes, the upper bit. I just realized that it was a newish development and wasn't sure if it was a sign of any vitamin/mineral deficiency or not. Or otherwise anything I needed to be concerned with. Glad to hear you think it looks normal. His behavior, poop, appetite, et al is all normal, so I'll continue to remain unconcerned. We're probably going to pay the vet a visit soon anyway for chipping and a nail trim, so I'll mention it then too, just to be sure.