Can anyone verify if the maps in the mirror link will work in MC 1.8.3?
They will work in MC 1.8.3, but some may be out of date. All but two of them, as DiamondLover said, are all up to date as far as Vechs has made them to. But some may be unbalanced for the newest versions, if that makes sense.
I.E. don't jump off cliffs in spellbound caves with the Feather Falling 5 boots, because.. well, you'll likely die, since it's outdated.