The primary influences for Mystic Manor's
architecture is one that has already been discussed
throughout this thread which is the Carson Mansion.
As for myself, though I too believe that mansion
serves inspiration for the Mystic Mansion, I also
believe this other mansion (which is also found
in California) delivers its influence onto the
design of Mystic Manor.
Particularly the "onion" dome.
This is the Morey Mansion.