Rewards of "Corporate Holding"?

I only managed to save 3 out of 4 freighters, too sleepy already to re-try. I got 10 Gattling Cannon ammos, 2 gold jewelries, and one other item, forgot what. What would I get if I save all the freighters? Anything special or hard to acquire from pirating?

Unknown. I've gotten all the ships through before, but don't remember anything special about the reward. Probably just some more stuff.