This is a phenomenal resource already, even in its incomplete state!
For example, I searched for Arthur Argo (great-grandson of the collector Gavin Grieg) and 45 items came up. Several were a 16-year-old Arthur singing at a People's Festival Ceilidh in 1952/3?, hosted by Hamish Henderson (and set up as a counterblast to the official Edinburgh Festival, with more political content and ticket prices aimed at greater inclusivity) -- listen to his version of 'Lord Randal' to the tune of 'Villikins and his Dinah'! Sounds unlikely, but it really works because he believes in it.
Then there were tracks which Arthur had recorded from singers such as Jeannie Robertson, Lizzie Higgins and his own father, John Argo.
And an 'icing on the cake' moment came when I found 3 tracks of Hamish Henderson, recorded by Arthur in 1960, which must have been very shortly after he had written the song that so many of us regard as the aspirational song for our generation - 'The Freedom Come-all-ye', Hamish sings that song, and 'The Banks of Sicily' (which he wrote after accepting the surrender of Sicily in WW2 and before they moved on for the Allied push into Italy) as well as 'The Baron of Brackley', which has had a special place in my repertoire since about the same date.
And that's the result of only one search!