Ok, I heard back from Martin @ Sheep Tapes, here's what he says:
...Actually i'm having troubles updating the Sheep tapes website, which is why I prefered to put it off. The reason of that is that i don't have Devil story DVDs in stock anymore, all has been sold ! I think there is one last DVD on sale here : Devil Story - 1985 - Beranrd Launois - DVD
We may print some others, we don't know yet. I'll let you know as soon as I have information about this !
Thanks a lot for your help and interest about this, if you want to pass on the information to the people who have interest for that strange little object that would be great :-)
Thank you !
Martin