@RetroWizzard@oldbytes.space @xexer@oldbytes.space
There is one available for purchase here: https://www.wtsretro.dk/shop/commodore-amiga/commodore/commodore-spil/c64-cartridge/harald-haardtand-c64-cartridge/
It's not that uncommon here in Denmark, and carts are relatively often put up for sale in various Facebook groups for Danish retro enthusiasts.