The one mentioned by 'Nailer' and the one currently discussed are probably/possibly one and the same being that which was offered for sale by Dennis Hiller a few years ago.
I think I probably still have his original advert. I know he did take a while to move it on, as although they are undoubtedly rare, as 'Trevorj' says they have little aestethic appeal, but are a great addition to any BSA collection nonetheless.