I have updated this old code to be fully functional with Python3.6+ and now can use NTLM without unpack issues.
https://github.com/genusistimelord/PySSRS

 

I will tell you this though. It was a mess to get everything working correctly as i had to figure out how Suds actully worked to fix pySSRS and then had to get a proper suds-requests which wasnt trying to install a old version of suds that was completly broken.