I'm afraid it is not possible to get patches after 1.05 if you have not registered the CD key. I don't know if thrift means used in this context, but if so the key has likely been used and you really can't do much but email support and hope for the best.

If it is a new copy, the CD key should be either in the box or and the manually, and if you email support with your email key they'll add it to this account and you'll be able to download the fully updated game.

Gamestop no longer takes retail Sins keys from players who still have not registered. Stardock is the only one that can give them the updates. Only already registered customers need use the gamestop app.