Missing Submarine Components

Not really sure where the correct place to post this is but our FC seems to have 'misplaced' two shark class submarine components several months ago. I've tried going through the history of both our FC activity and the chest and neither go back far enough to give me any clues as to who may have them. Only a few of us really use the workshop and no one says they have them. Chances are whoever put the coelacanth class bow and bridge on our current active sub is who has the pieces. any way for me to track that information down or is this an unsolvable mystery? These are expensive in game items and require teamwork to build; would be a bummer for us to just lose them.

Check the fc chest, have everyone make sure they open up all their retainers & chocobo saddlebag before doing "/isearch shark". If nothing turns up then your last hope would be a GM if they happen to have logs that go back that far, but for privacy reasons even if they had that info they may not be able to provide it.