The lockbox does contain a couple items that could plausibly belong to the villagers Mhavos & Ellis have interacted with, but it also contains a number of items of jewelry and trinkets that are certainly out of their price range. The villagers will vary between defensive, combative, and chagrined when this is revealed, with a couple people accusing them of being thieves if they won't give back the valuables that pretty plainly don't belong to the folks claiming them. But cooler heads will prevail (unless you'd prefer to escalate things), with an older woman essentially thwapping the most belligerent fellow upside the head with the air of an exasperated aunt and telling him to leave off and be grateful, at which point he will at least do the first if not the second.

In addition to the collection of small valuables, the lockbox will also contain a page of what appears to be an inventory. It won't be possible to match it up precisely with the current contents of the box, but there is a notation that may stand out as odd: an entry for a jeweled brooch in the shape of a rooster is crossed out and marked "return approved by Raeus at request of 'the Helmsman'" with a question mark in a different hand afterwards scribbled out.