In 1967 I was a student who, through a friend of mine, took part in a trip behind what was then "the Iron Curtain". My friend's wife was a student at Manchester, studying Russian, & wanted to travel to Russia. She had no money & worked out that the cheapest way to do it was to organise a student trip going there and this could be done by us all buying places, which included the purchase of a double-decker bus, which would be our mode of transport. 2 engineering students at Manchester, who were to be the drivers of the bus, were dispatched to buy a bus, which they did from a specialist scrap yard. They chose what was known as a "country bus" as it was a bit lower than normal double-deckers, having a sunken walk-way & long bench seats on the top deck. Our route was plotted by the AA to avoid low bridges [they only got it wrong once - which took a chunk out of the top near-side corner of the bus!] & was made easier by the slightly lower than normal double-decker.
We travelled for 6 weeks, visiting Poland, Czechoslovakia, the Soviet Union, Hungary & East Germany en route.