I have a question in regards to this enclosure, actually not really in regards to the enclosure, but to the subs...
Shouldnt you reverse the rubber ring around the outside of the sub? I have a type R, and I know what the front face looks like, and it would make a LOT of sense to everse the rubbber so it sits flat.
Not only would this seal the area better, but it would look a lot better as well.. you could cover the screws then.
Peace.