The UC Berkeley copy is signed; does that help? Also there's one at GWU, one at Northwestern, UMCP, UPenn, the National Library of Israel, and NYPL and Harvard (of course), but you probably can't get to those, and at Oxford, too.
I'm assuming your are looking for 'Avi'; it looks as if exceprts (maybe) were published in English as 'A Dream Come True' (George Mandel, ed. Westview Press 1993), which is available used in the usual ways. I can't tell if this later one is actually what you are looking for, but it's worth a shot...