@ Pieter Boelen What can be the Problem be?
I have not a clue. Would need to be investigated.
@all Hello how can help us with that Problem!
I can pretty much guarantee you that nobody else currently active here knows either.
My time is extremely limited and if/when I finally do find time, there are a huge amount of more important things to be done.
The whole "what items are available where" system in the game needs a completely overhaul, for example.
But it has needed that for years, but if there is nobody available to actually do it, then of course it doesn't happen.
A few options for you:
1. Investigate it yourself (WARNING: This will be far harder than "adding a sword into the game"!)
2. Somehow find somebody who can investigate it for you (don't expect too much here)
3. Make it a unique weapon that is not available
anywhere, then add one of them somewhere into the game
(give to a specific character/add dialog option to buy it/put it in a specific chest or random item locator/add a low chance for it in the Treasure Quests)
4. Live with it being available also from non-pirate stores