Thread:Nakano15/@comment-25154028-20151004043513/@comment-3509554-20151007033302

Well, placing the 1.2.4.1 content folder inside Terraria folder, and moving 1.3.x.x Content folder inside Terraria folder and overriding the old folder will cause both 1.2.4.1 and 1.3.x.x contents to be disponible for both mod versions.

The only problem is that some items and npcs may have sprite bugs on one of the versions.