The original maps belong to TSR, this is just a fan recreation in a more modern digital format.
Thanks, I made the SP maps for a friend and then got to run the game for him & his friends. I have done several of the old modules and this one was the best to work on so far. Often the written text and the cartography don't match very well. It is not uncommon to get text that says, "In the room are 3 beds, 3 chests, 2 bureaus, an armoire, 2 desks and chairs, a table with 4 chairs, and a couch." But, on the map is a 10ft x 10ft room with a bed and a chair.
I just finished running this game online with Roll 20, it was fun.