[propbeanie]

The dual deck gun is "built" in the UpgradePack.upc in the Data \UPCData \UPCUnitsData folder. You'll see an UpgradePack for the Stern Gun, one for the Bow Gun, and one for Bow and Stern. This applies to stock and most mods for the US side, especially the 5 inch, 25 cal version of the deck gun. The dual guns for the pseudo Narwhal of TMO is actually a dual 4 inch 50 cal gun, while the dual gun for the Narwhal Team's "Bonus Mod" is a 6 inch gun, with newer 3D artwork files, and changes in the Weapons.upc file. I do not have a Dark Waters or Op Monsun install on this computer to be able to look at the files there, but I do not see a dual deck gun for the GE in Stock.

As for the mount itself, there is a M01 and M02 node on the submarine's hull. There would be two approaches to the actual mount. You would add a node to the hull to attach your platform to, or make it a permanent part of the hull. Then you could either then raise the M01 and M02 nodes on the hull to a "higher" "Y" axis location (lots of guess work and experimentation) to coincide with the platform, or better yet, either move M01 & M02 to the platform itself, or add M03 and M04 nodes to your platform, and in the submarine's upc file, mount the guns there instead of M01 and M02 with the "ExternalNodeName3D=" lines of "UserPlayerUnit 1.Compartment 7(8).WeaponSlot 1".