That's fascinating stuff. I hope someone somewhere is bringing that kind of material together and preserving it, and passing on the songs produced.
I wholeheartedly agree. About two third of the ballads are preserved in the new MacColl songbook, but the rest of the ballads and especially the texts in between are not preserved yet. I'd be one to buy a libretto, though I guess it would have to be awfully expensive due to the amount of work involved.
The radio ballads were compiled with such a tremendous skill that even when the theme is out of date I still sit spellbound when listening.