Over the Thanksgiving weekend, like a main course of ("T"-for-) turkey, I dug into making a start on this build - T(3)-class sub, as-fitted when she sank the IJN cruiser Ashigara, off Sumatra 6/8/45 - using our idea to bash the Revell-Germany 1:144 (German) Type 206A:
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At right, this stub was then conservatively - gradually - shaved down (top) until producing a stop at the optimal realignment of the aft hull section - when compared, of course, against the drawing - to which the aft section was then angled and secured, while braced by tape, as shown at middle. At bottom, abaft the (now) keel, the new alignment/attachment was strengthened by beginning to fill the remaining voids - though carefully avoiding any pressure which might force the alignment back open (or crooked).
Even with the above still hardening/setting, already it was possible to begin Step 2: the lengthening of the central hull:
Click on Image to Enlarge
At bottom, mounting collars were fabricated and installed in both openings - aided greatly by first sizing with a piece of paper (white, in background), forming a template for each collar of 0.025" (white) plasticard. Smooth curvature was introduced by rolling each under a smooth drum - e.g., small bottle or spray can - pressed down on a surface having some give - e.g., stacked/folded newspaper, or a mouse pad, etc.. Curvature was made fully complete only during attachment; "spot-welding" with superglue, beginning at the center and working symmetrically outward - 1/8 of the circumference (or less) with each step - while pressing the strip down with a knife edge, flush against the tube. Optionally, after the above - which is not actually "welding", but tacking - the collars can be well and truly - using a "hot" adhesive - welded down, though only along the inside lip, as the outside seam should be kept maximally clean, for subsequent mating with the hull-insert (not shown).
Clearly, you can see that's exactly where this is headed:
(And this is actually not a bad way to depict a cutaway sub, looks like!)
Note the tube looks a bit wider than in the drawing - and this was expected, as the Revell-Germany mold actually scales out 4.2% larger than needed for a 178-scale T(3). (Additionally, the macro-mode of my camera, above, may further accentuate the effect.) Not to worry in any case, however: once stoutly constructed, in the proper alignment, the entire hull can if need be pinched back 4.2% narrower. Only if needed, that is - since it's entirely possible and even likely that the overlying saddle tanks, top casing and heavy keel could, between them, hide this discrepancy so much as to basically render it (visually) undetectable.
Meanwhile, the required hull insert - another simple tube, its diameter determined by fitting against the existing tube-ends, and length determined by overlay directly on the drawing, as shown - can now be fabricated and installed. However at this point I had to break off work.
Look for exactly that last - and more work - Coming Soon. Happy Thanksgiving, y'all!