I would strongly suggest against updating older models on cgtrader. I have very negative experience with this - i have updated several previously successful models and all of them either fell dramatically in search results, or even disappeared from search altogether. In any case after models update their sales stops almost completely. It's much safer to publish updated asset as new, although lately it doesn't matter much, since new models doesn't sell on cgtrader as well. Personally i stopped make new models for selling and not planning to resume this in the near future, unless cgtrader will pull the finger out of their ass and start fixing all the mess.