I'm not sure if there were circumstances that I wasn't aware of that made it possible but I recently helped myself out of that same problem. I got an iPad 2 which was passcode locked for sure and the screen said it was disabled with what i thought was an icloud message from the individual who left it behind. I found this iPad at work, turned it in, and waited the 60 days for no one to claim it and believe it or not they gave it back to me. I was told the same thing, so it sat in a drawer for almost a year. With the 9.3.4 update out to kill jailbreaks and the beta ios 10 floating around, I learned that Apple would sign an install of 9.3.3 through itunes going backward from either 9.3.4 or 10. So since i couldn't even open it I tried something a little redundant. I was still sol to do anything to it in recovery, so i downloaded the .ipsw's for 9.3.4 and 9.3.3 for this iPad 2(4th gen) ios unknown and put it into dfu mode. Then i chose to restore the iPad completely to 9.3.4 through itunes and it let me do it. After that I immediately did the restore + shift to choose the 9.3.3 .ipsw from my files and it let me do that as well. When I set it up it was brand new with no trace of any former owner. It worked for me, maybe it will work for you too. Good Luck.