I saw the same issue in the keyhunter github saying you need to use python 2.7.3. I did that but same thing.
How about a lower version like the exact python version 2.7? Here's the link
https://www.python.org/downloads/release/python-270/I can't find much about this recovery tool but it looks like it can recover private keys from accidentally deleting the wallet.dat.
Would you mind trying if you have an extra laptop or PC install windows 7 OS and then install python 2.7(Only do this if you still have a syntax error) to make sure keyhunter will work then put the image disk backup on that PC and try to recover it or make the HDD as your external and then run keyhunter.