I was watching some First Doctor material on netflix (sorry I forget the episode) and I notice that the Doctor and Crew exit stage right (doors on the right) in some episodes.
Now you could argue that we are simply viewing the Tardis from the other side but sticking to an real world production point of view - when did the shift over to exit stage left occur? or was there a mixture of the two for a while?
During the Harnell era all the TARDIS doors in the interior shots are all on the left, there wasn't enough stage for them change it for one thing. I don't any exits from the TARDIS being on the right even on the new series. They've never had a 360 Degree TARDIS set so the door is either on the left or in the center.
They exit to the right at the start of the Sensorites.