Found the answer to my own question In this version the individual lists are stored seperatly, then combined in a single list. The presize variable controls all size functions in the code, so if you want to change the size of the lists to 20 set presize to 21 (20 mats plus the list name). The rest of the code now appears to work, and I've added in the correct lists for V3 skins and heads (or at least the ones I wanted to use) Also added the self.Update() as above