Here's a cover page from a very neat technical manual done for the Haunted Mansion in 1969.
While working on the first Mansion for Disneyland, WED was well aware they would soon be building Walt Disney World's, Magic Kingdom. It too would feature the spook house so they went ahead and built two of everything.
The WDW Mansion was actually the first completed attraction for the new park. While they had time after the late 1969 opening of Disneyland's attraction, WED completed this through technical guidebook for the installation of the second Mansion.
It features many key effects and animatronic characters of the ride in schematic breakdowns.
If you ever win the lotto and decide to build your own Haunted Mansion, you'll definitely need one of these!