I installed your mod over TMO 2.5 and OTC. It seems that the game files have been modified ok, but the weapon is conspicuous by its absence

I installed it in port, partway through a career, just as I changed from an S-class to a Salmon - Would that make a difference?
Grateful for any pointers you could throw my way. Normally I'm a big believer in realism, but my own personal ethics have a clause that exempts rotary barrelled weapons
*edit* Problem solved. It completely slipped my mind that I'd have to go to the weapons screen and install the thing as an upgrade. <facepalm>