For the comb seal and the mating surface under the hatch I used very narrow door weather stripping from the hardware store. I think it's 1/4" wide and it has the self sticking back. I'm not sure if it's closed cell foam but it has a very fine texture.

I worked it down around the lip of the comb and then turned the hatch over and put a mating seal around the inside of that lip. It also has a double rubberband to hold the hatch nice and firmly in place.