Dando Shaft were an late 60's/early 70's British progressive folk band from Coventry, relying on their own unique brand of complex rhythmns woven with guitar, mandolin and violin, one of the best bands of the genre. Even though they never went electric they still gave off the same energy as Fairport Convention, Steeleye Span and the better known prog folk bands of the time.
Lilting, complex, unusual, they certainly managed to squeeze into the term progressive
They released three albums and split in the mid 70's, two members went on to make it bigger in the band Whippersnapper. Polly Bolton, their great female vocalist would also do pretty well as a solo artist.There was a brief reunion in 1977
You can get some of their tracks pretty cheaply at their official website here