Fred Wedlock certainly recorded "Bristol Buses" but the writing credit is Christmas/Wedlock on the sleeve of his "The Folker" LP, and just Christmas on the label. I've always thought of it as a Keith Christmas song, anyway, though in style it's much more Wedlock.

Can add:

"Midday Eastern National" by British band Limey from an a mid-seventies album, and "National Express" by Divine Comedy. There is also an album called "Tribute to a Bus" by 18th Dye but it doesn't relate to the content (maybe a reference to a tour bus !?)