Thank you, James, for this helpful information.  When I did a Google search
after Steve's original announcement of this set, I didn't find anything like

Unfortunately, if what the folks posting here…

… say is accurate, the recordings on the USB drive are MP3s.  One of those
folks also provided a PDF of the track listing, and aside from two Watts &
Wilson B-sides, I don't see much here I do not already have on LP and CD. 
Certainly, no recordings from before Paramount launched their 12000 catalog
series.  So I will have to keep waiting to hear "Up! De Valera."  :-)

What the mastering company has to say about this project is here:

Apparently, Christopher King did the original transfers from 78 RPM discs,
but that begs the question of whether all the source material was in fact
drawn from 78 RPM discs.

I adore Watts & Wilson, but I will pass!

Best wishes, Mark