Wildspear's right, we needed a Gato/Balao/Tench section in the Photo Gallery. Well done, Rokket !
But, as Rokket pointed out, there are actually three classes of boat. And, in most cases, there are more differences, between individual boats, than between the three classes. Plus the differences between which yard built a particular boat.
The most massive change, you'd have to make to the model, is to change an Electric Boat (EB) Gato into a Portsmouth Tench. All other change would be for an individual boat.
Mare Island used the Portsmouth design, for the most part, and Manitowoc was EB design.
And the BIG differences? EB had a starboard anchor, Portsmouth, port. Gatos & Balaos had a rounded chin while the Tench had a sharp chin. That's it.
Everything else (Flood Ports/Valves, Limber Holes, Armament, etc.) was up for grabs.
I had to make that change, since I'm building a Portsmouth Tench. Give me a few minutes and I'll post, what I did, on the Photo Gallery - Gato.
DBF,
Mike K