Questions on the old Geodimeter stations?

Thanks for the very detailed responses! I actually ended up buying one but now trying to determine what exactly it is! The tag on the bottom only indicates "machine control" as the type. I see that most will indicate their model. for reference, compared to the pic that Eddy put up, this one looks identical in every way other than it is yellow. It is a robot. No time like "after" you buy something to figure this stuff out I guess....lol

This one does have the serial port on the bottom which probably indicates the vintage a bit.