Terry

If you're looking for traditional singers, the best place for English and Scottish (and quite a lot of Irish) may be The National Sound Archives, kept in The British Library. Alternately there's Cecil Sharp House.

The National Sound Archives Catalogue is here Cadensa Cecil Sharp House is hereEFDSS

A useful resource for information about commercially recorded singers is the Musical Traditions site.

You could start with names like Harry Cox, Sam Larner, Scan Tester, Cyril Poacher ... the list goes on

Happy hunting!
Ian