I have some plans that I downloaded, as well as a set in a book I purchased from a memeber here, Ubootwaffe. (those plans kinda got me obsessed with this boat.)
There are variations from plan to plan, as well as discrepencies b/w the plans and the photos I've found. My Brother in Law is in London, and said he'd be willing to go to the Imperial War Museum and get additional photos, and maybe measurements if possible. In the meantime, here are 2 drawings made off different plans that illustrate an example of the discrepencies.
In this sketch, made off an image form Ubootwaffe, I drew a circle with a 533 mm diameter. I resized the image to tha tthe torpedo was sized to match this circle. I drew a vertical line and rotated the image so it was oriented with this line and the torpedo was concentric with the circle. I matched the verticle line top and bottem to the image, then drew arcs to match the image. I did redimension the features to give me these nice round numbers, but they match up pretty well. This gives a hull 1000 mm tall, with the upper half an arc of 480 mm ( matches the stated hull dia. of 960 mm) but the lower arc is 575 mm, with its center above that of the upper arc. the torpedo center is 520 mm from the centerline, and 275 mm below the center of the upper arc, 255 mm below the hulls center.
This sketch is based off an image from the interwebs (I don't recall exactly where at this point.) This and others show the hull being circular, with cutouts for the torpedos. again drawing a 533 mm circle, scaling the picture up to size the image. Here a 960 mm circle matches the hull very well. I didn't straighten the image, but matched one torpedo and the hull. I added another 533 mm circle, matched it to the other torpedo, and added a centerline. I drew a centerline through the 960 mm circle, and made it perpendicular to the torpedo CL. I measured the distance from the left torpedo to the hull CL, and made the second circle the same distance The 510 mm dimension is the same as the first sketch I posted, but the CL distances vary, as well as the overall hight.
I am wondering if anybody knows much about this boat, which profile is closer to the actual one. Any advice or opinions would be welcomed.