I'm reviving this thread because perhaps more people have
now watched the show and recognized the tunes.

Obviously the theme is a variant of 'Blow the Man Down.'

Lately one of the incidental tunes has been a fine anglo
concertina rendering of the minor-key air to the transportation
ballad '10,000 Miles Away.'

But I'm still not recognizing a couple of the Morris tunes
as well as a real nice hornpipe played on concertina.