how about a place in-world (perhaps the bureaucratic hall) where one could drop found objects and have them returned to the previous owner.
perhaps it could work like some of the communal places i've been -- when someone drops something in the lost and found, they have an option of being anonymous or letting the previous owner know their name.
could also have a time-out policy -- e.g. the previous owner receives a message that lost property may have been returned and they have 30 days to claim it. after 30 days, the finder has first dibs on receiving the item or donating it to a chicken orphanage, disadvantage pig farm, etc.
i know a lot of people hide stuff in-world for others to find. this would be an option for when one finds high-value or unique items that may have been dropped accidentally.