Right Elf Charm possibly in another player's inventory (impossible for them to log back in)

Hello, need help with item recovery. 5 -6 years ago I played in a shared world with an ex. After separating 2+ years ago, I managed to save and import the shared world's game files so that I could host it and play on my own instead. I really loved the game and wanted to finish it regardless. The current problem is I can't find the right elf charm to complete the full set. It is not in the original spawn point at the tree stump chest (I've checked). I have also tried game repair by recovering backpacks to no avail. It is not in any of the storage chests/furniture at my base and I never put items in pets storage so it did not glitch out either. It is also impossible to contact this person to log back in just to retrieve this item. I've played this game for a very long time since then so loading an old save is also a no-no. Please advise thank you.

I play through PC-Steam
I mostly play alone but host through multiplayer for occasional friends
Have played for at least 300 in-game days