Did you know that Dummiesman left the community like 2 or 3 years ago and he probably doesn't care if you post his mod again.
He's still active, he just doesn't make mods anymore. He's now making mods for Midtown Madness I believe.
Well yeah but technically he has left from here. I'm just going to say that if King Games is going to ask permissions from him it's not going to happen cause dummiesman doesn't react on this community at all anymore
He's unfortunately taken a hostile stance against this community, I doubt you'll ever get permission from him. Ideally if you can release patches without the original mod, no one can contest that. But even so anyway you release it should be fine.