Hi Dan,
I just returned from a trip to Chicago to visit the U-505, quite an experience! A beautiful boat. I can't help with any line drawings but I took lots of pictures of the inside and the outside of the boat during the guided tour.
I don't mean to hijack your thread, but one of the former US submariner volunteers asked me if I knew what the two appendages are on the lower bow of U-505, one on each side, anybody know?
Regards,
Brian