Here's what I have so far
10 Mythic Pounds of silver (or their equivalent in portable wealth).
One 20 foot boat, with sail and two pair of oars.
Two grogs, one fighter and one servant.
The Analects of Tytalus (summa on House Tytalus Lore L3 Q8, tractatus on Philosophiae Q8; tractatus on Order of Hermes Lore Q6).
The Book of Instructions (no educational value whatsoever)
That's what he left the Ushant with. Should be added the proceeds of his exploration of the sunken covenant. I'm sinking more silver (probably not coin, but silverware or other valuable objects), and maybe some vis: Aquam vis found on site, or the proceeds of the sale of some mystery magic items -although the rules on magic investigation don't make mystery magic item attractive for the buyer: you lose at least one season of investigation which you could have used to extract vis...)