Im not sure if anyone has ever pursued a player for including things in their MOD. Since no money is made on it, and we are talking really old stuff, Im not sure what the point would be.
HOWEVER the official answer would have to be YES that would be a violation of the authors rights. It would also be very unnecessary. Since we are talking about 2D game tiles there are tons of games out there which have been given to the public domain. There are many Online libraries of tile pieces.
And you would be surprised how often you can contact an author and just ask. Even with very popular titles like MM3. In fact, please do that. While you are asking be sure to mention how popular the game is that is able to use their tiles. It might draw a few of them here to take a look.
