Right now if you complete a Skeleton Fort you will get tons of items and a Stronghold variant for each item type, making it very lucrative to raise your reputations. Sadly, this only works for the 3 original companies since besides the mermaid gems (that are basically a wildcard) you don't have any item to turn in for HC reputation.
I was thinking in a couple of solutions like including a barrel with fishes or something like that, but I think that a "physical" item will be a better fit from a risk/reward point of view since you can basically carry the fishes in your inventory. Lucky for us, you already have something that could be repurposed for this: Treacherous Plunder.
I suggest a new Stronghold variant of those items like a Stronghold Fish Bones or something totally new like a Meg teeth, with a price and reputation equivalent to the other Stronghold items.
