Actually the service wasn't even to Sidmouth Junction, but only to one stop up the line, Ottery St Mary, a small village and junction for Exmouth. Often there was either a change there for the main line junction, or a tedious wait while the separate portiond from Sidmouth and Exmouth, in deep winter often just a single coach each, were marshalled together to continue, with all the panoply of two (sometimes three if crossing a southbound train) big 80xxx tanks messed around, and in aforementioned winter the staff outnumbered the passengers.
The Devon General bus company, for some reason, always seemed to provide a much more frequent service all round than the Western and (especially) Southern National companies, whose operating territories surrounded them. This led to Exmouth and Sidmouth having frequent buses in several directions, right from the main streets and seafronts of everywhere, far more frequent than nowadays. They even had a bus garage in Sidmouth, where the Lidl is now.