You can patch 1.0 or 1.2 all the way to 1.4 (full) bypassing 1.3 (which is included in 1.4).
1.5 is the latest full version from any store. You CANNOT, or should I say DON'T patch 1.5 with a lower version! D U H
Vartugg has to give you the password, and he won't do that untill you get his eye from Voratus.