I think it should be in the rules!
Very Important!
Instead of ONLY the last owner of the art piece i THINK it's NECESSARY to keep track of as many previous owners as possible. So a list. Made by, owned by, bhought from, owned by etc etc just a simle list of names instead of just the last previous owner.

How would this be implemented? Would it be a list managed by the people themselves or would there be some sort of system in place?

Managed by people. Just c/p the last owner and add your name to the list.
I guess links from where u bought it would be to much, but still, this could be much easyer to track in case of stolen textures, etc.
just add to the rules to add your name to the previous owner instead of just writing the last person who owned it ( if u know what it is ofc)

In all honestly I like this idea and could see it helping out more. Though I can see it becoming very hard to keep up with it in the long run. Just one person forgetting to carry it over and selling it Via PM would ruin this. And for us users without ToriPrime we can't search the forum as easy as others in order to find the last thread where it was sold.

Also maybe tone it down to like the last 3 or 5 owners of the Set/Texture.

You could make the set be in a zip, and have a notepad file there with a list of owners, and whoever buys it simply adds their name.

Yeah kota, if people loose track that's life. But u can always go back a few steps, search for a thread and get way more info from one thread then tracking down a head in multiple threads, looking at dates and such.

Example:
Artist:Pheature
Previous owner:HiPower, Tomiiiwhaw, insanity, imapirate
Size: 512x512
TC
next person that buys it should add name to this list. Idk it might work in case of lost files to.

Yes I understand what you mean, but what I'm saying is what about when people sell the texture Via PM and don't create a thread for it. Then if the next person to sell it doesn't update the information or it gets Traded by PM again then all of a sudden you don't have a way to look up who the last few owners were.

Yes you can ask around, but more often then not people will give you the answer "I don't remember who I sold it to".

no one would do this people from what ive see most times just do the bare minimum. i don't think it would help staff because the list could be fake or one of the names is incorrect the last know owner is usually what people go by anymore information than that is extra (not really needed). you cant expect people to keep a list of past owners of a head
i think it should stay if you can keep a list good for you if you cant no biggie