Let me add a couple of points about the Yankee Modelworks pressure hull: 1.) it only has to look right from the sides, if you use an aftermarket deck with all the slots opened up, even with very bright light you won't be able to see anything by looking in from the top. 2.) In one way it's wrong: use plastic card to make an oval " coffer dam" of the same dimension as the conning tower (minus the Wintergarten), as the base of the tower went down through the deck and rested on the top of the pressure hull. Then you can take a power drill and cut out a nice large area for your periscopes and don't have to worry about getting the alignment exactly right or about building some kind of ladder coming down from the conning tower hatch. 3.) Use a bit of doweling to represent the pedestal for the deck gun (it fits in the base molded on the top of the pressure hull - look at it, you'll figure it out easily). Also, and this is a pain in the butt, you'll need to glue a little strip of Plastistuct paralleling the vertical rivets along the long slot above the saddle tanks (otherwise there'll be way too much flex in the upper hull sides), and you really should have these strips alongside each limber hole for the rest of the hull as well. Paint the strips a dark color along the slot and they won't be too obtrusive.