Griffo has not been released by any major foundry. Mardersteig was
apparently insistent that none of his types be adapted for
photosetting, which he deplored. I believe Monotype had to resolve
this issue before releasing Dante in PostScript (and Dante had been
licenced by Monotype for metal).
So, on the face of it, it would appear unlikely his estate would
release the original drawings for any of the types he created purely
for his own use (Griffo, Zeno and the Pacioli Titling).
There is no reason why Griffo could not be recreated from printed
samples (except perhaps the astronomical cost of obtaining the
relevant Officina Bodoni titles). I don't know anyone who has done