Looking at the artists and considering the era I would guess that a lot of these are transfers from 78s. Guessing some more, I would imagine the recordings of greatest value would be any that might not still be around on shellac. So you might start by talking to a collector of jazz 78s. Continuing to throw out WAGs I would suggest that in the end the collection as a whole with all of the documentation might have the most worth, as a great example of the tape exchange concept.