Best I can tell, picking up Ancient Jawbones and Ancient Pottery, adds neither to your inventory, but often increases the number of "treasurechest" that you have. And the "treasurechest" only increase from events that don't mention them.
Edit: Pretty much all battleaxes show only the hilt in inventory (but click through fine), reasonable enough, but also at least one pommel shows as an error on weapons (hand axe and couple battleaxes, the click throguh detail on the following matches the inventory pic.
