Well, the Telecruiser was definitely outside the building, at least for a while. Perhaps it was used for technical support, or just a microwave link. I really don’t know for sure. The Marconi MK-IV cameras that it used are "portable," at least in the 1960's sense that "they had handles on them.

So were the Camera Control units and just about everything else. It would have been fairly easy to remove them from the bus and take them inside.
It’s just a guess, but perhaps they removed the equipment from the bus and placed it in what was to become the control room? I remember seeing the black and white cameras in the actual studio which was always visible from the mall’s hallway. I’m pretty sure they were Marconi’s, which are fairly unique looking and couldn’t be mistaken for an RCA or GE product.
My recollection was that until the color equipment was installed, the control room area was not visible to the general public. I seem to remember brown paper over the windows to keep prying eyes from looking in. After the studios went color, the paper was removed and the control room became quite a showplace.
I remember asking somebody at WFAA (I have no idea who) why the show as black and white. I was told that they had ordered the new color equipment but manufacturing back-logs and delays prevented delivery of the equipment until after the show was scheduled to air, so they did black and white as an interim fix.
Here is a thought: Maybe they used the bus as a temporary control room while they were installing the color equipment? I really don't know, which is the reason I posted this in the first place. I’d love to find out more. There isn't a lot of accurate information about the vehicle and its history.
One thing I do know is the bus is in my garage in East Texas, undergoing a restoration...
www.telecruiser.com It is one of the very few surviving TV mobile units from the early days of TV. This one dates to 1948, when the station was called KBTV.