Submitting customs made by someone else with their permission?

[Fawfulthegreat64]

I've been using a model for a while in my renders that I converted from a Smash mod, but the model itself isn't made by me. I've been asked a few times about the model but never have any download for them other than the Smash mod it came from. If I were to reach out to the creator for permission, would I be allowed to upload it here with credit? Or do they have to make an account?