Posting for transparency.

You cannot recieve a Threetoothjoe charm if you already have one (whether found or bought) in your inventory/gallery. This means that you can technically receive mulitple providing they're not on you at the time it 'drops' again.

Not sure if this is intended or accidental but it opens up to abuse meaning that people can get multiple.

(have chat logs from our discussions this evening if needed)

Edit before I get lynched: Not asking for them to become unique or untradeable but vae's intention was to make it one per player.