heres my second build of the u2540 some of the photos show some mods i have made 1) is a brass plate with th antenna wire under the sail the periscope screws into this rather than have the whip anteena at the rear of the sub, 2) is a waterproof mylar speaker under the sail for the diesel sound generator ( thanks to another post on rcu) and finally the detailing of the weld lines going very well.