I've never understood why our collection (around 500 tapes of English and Irish field recordings) have never appeared on these lists - it is documented as the Carroll/Mackenzie Collection and part of the BM/NSA collection.
Via the previous curator, Lucy Duran, we donated our recordings to the then National Song Archive in the late 70s, effectively turning it from what was then largely an African/Asian anthropology/musicology archive into one catering for all traditional music collections.
It was through the efforts of people like Lucy Duran, Reg Hall, Malcolm Taylor and others, us included, that the 'Bright Golden Store' project was initiated which brought in some of the collections mentioned in the BL index.
Eventually the project ran its course and the money dried up, still leaving a huge number of collections untouched.
I don't think there are BBC recordings that date back to the 30's Charlie, but if anybody is interested in a sadly neglected English collection, the NSA/BM holds the Percy Grainger Collection, made in Lincolnshire around 1908.
There are shanties in the massive J M Carpenter Collection, made in Britain in the 1930s and now being worked on, I think in Aberdeen.
There is a copy of this at Cecil Sharp House.
Jim Carroll