This could be done in part, because the equipment was very inexpensive. Not much money was involved in tooling so that basic changes of that type could be accomplished.
When you are on tour in the UK it takes a few hours to get anywhere. A lot of the time you can have a beer, close your eyes for two minutes, and then you are there. In the U.S. it is much more like a road trip as all the cities are so spread apart.