I just had my first run in with this error 53. We completed the screen repair a few months ago and he has had no issues with the device since then until the update to 9.1. We tried a few things first like DFU and recovery and RECBoot.
Here is what fixed it for me: We clipped in a new home button flex cable with the original home button and the replacement screen. We did the restore again and it worked! Took out the home button flex cable from back plate and reinstalled the screen and it is problem solved.
Hope this helps you too.
Brian