Whilst I understand the concerns of mistermike, I rather think that we can treat these tapes in a similar way to 'official' bootlegs.
John The Revelator is a Dutch band that has its roots back in the mid to late 60's and Tom himself (who recorded these tapes) has been their mainstay since then. They are very ardent fans of Peter Green, and have been since those original Bluesbreakers days.
You can find more about them here:-
http://www.johntherevelator.nl/
and read/listen to the section dedicated to Peter here:-
http://www.johntherevelator.nl/history/peter_green_
As a disclaimer, I have no association with Tom or the band. I am just providing some details.