After much prodding, I have decided to upload the design for the cannons I am putting in my battleship Mikasa. This is pretty much the final version, exactly as I plan to install it, however it may still be subject to change. As it is a twin 7/32" cannon with a 4 inch magazine diameter, it is suitable for almost any warship that needs twin 7/32" cannons. The accumulators are simple copper tee fittings, and can be installed in several different orientations.
A rough draft assembly instructions are included in the file, along with a partial parts list. If you want to build these cannons, please provide feedback on both the design and instructions.
I plan to release further Big Gun cannon designs as I make them.