Murray, I've talked to several people about Lead Belly's guitar. As I understand it, the Stella was bought for Lead Belly by one of his admirers in New York. It is currently on display at the Rock and Roll Hall of Fame in Cleveland, Ohio, USA.
There is occasional talk of stringing that baby up and inviting several current blues players to give it a whack so to speak and recording the results. This would imply that there is something more to the guitar than just nostalgia.
When I talked to others about duplicating the sound of Lead Belly's it was suggested that one important factor was that the Stella has "ladder-bracing" as opposed to the traditional "cross-bracing" of most of today's guitars. I was given to understand that this would emphasize the midrange tones as opposed to the high's and low's.
I will watch for words from those more knowledgeable than I.
Roger in Baltimore