I missed Cecilia Costello? Not for any reason of choice but because there are just so many trad performers whose work is thus hidden. The Musical Traditions site has a traditional discography:

http://www.mustrad.org.uk/discos/tradisco.htm

Scroll to Leader in the index and just look at what's lying around in a Harrogate shed instead of being out there as a source for today's tradition carriers, not to mention a source of income for those revivalists still around. While Bill Leader's company was still extant no-one imagined the possibility that this rich source of material would ever disappear. Just as no-one questioned the terminology of contracts that didn't provide for the return of rights to the artist if a company ceased trading. Today is a different age but one in which there is still room for justice, compassion and common sense.