In fact they appeared many times on CMF. They also had their own radio show:

http://genome.ch.bbc.co.uk/search/0/20?adv=0&q=pennine+folk#search

My Kind of Folk - THE PENNINE FOLK

BBC Radio 1 England, 12 March 1969 19.45

http://genome.ch.bbc.co.uk/d1be8a22ef2642c5a81bda4713e9e36c

And they featured on Folk on Friday

http://genome.ch.bbc.co.uk/dd0157eabe104e639faa5f35549adc84

CJB