I have been unable to get any more information or see this programme, which is based on a book written by my Grandmother (real name Daphne Holmes) and is based on the true story of a few years in her life when her family - including my father and two aunts - lived on a converted bus and travelled around the country. Mostly because they were fairly poor, and the bus was available, but also because my grandmother and father were a little 'alternative'. My dad spoke about this a couple of times, and remembers going to see the filming in London when it happened. Family legend relates that he broke a camera - more than likely!
The book was once a text used in schools, and was widely published, although is now not available, although my aunt has a Canadian copy. I have no information as to whether the programmes still exist, or were destroyed by the BBC.
If by some miracle you stumble across this and have more information, let me know!