Final Boss of "The Twinning" Hunting for lore (Spoilers)

[Iscah]

Right, that is the "inventory" that the bottle does not show up in.

Not necessarily - as far as we know, it's a recording device, possibly a computer - the same design as the Omega datalog terminal currently in Rhalgr's Reach. Not that it actually matters, but all we're told is that there was an inventory somewhere of things they had on board the "apparatus" (presumably the tower / time machine) when they sent it back in time, and it did not have "message in a bottle" listed on it. It could be a paper list for all we know (or need to know).