Nothing can be done unfortunately. Each head would have to be proven to be made by the original creator and checked to see if it was already uploaded. It's just a bunch of extra time and effort that's not needed. There's no way we're going back to the waiting a few months for a custom system. You just have to hope the players will learn to respect your work some day and stop thievery. I used to steal customs when the system came out, but I refunded every single one of them and only upload stuff I make/hugely edit now. I regret what I did before because I know how horrible it feels to have your work stolen and I should have known better.