The first one definitely reads Mdina. :thup:
It's a factory mark, though, not a signature.
Pink mottled stuff dates from the '80s onwards, (my interest is in much earlier stuff. Neither mottled or pink do anything for me, I'm afraid.)
I'm pretty sure the second one reads Mdina too, but would be a good bit later than that. I'm afraid I don't do headstands. I did turn my head upside down, but went dizzy, which affected my reading!