When trying to add the red scarf to a Pokémon in pkhex, for the Gen 5 Games, BW and B2W2, it says it is invalid and the held item is unreleased. You can get the red scarf in those games though, no?
I just noticed a new bug with currency when editing older game saves. Specifically Pokémon Crystal as well as a few others. In Trainer Data Editor, the text box next to the $ sign is just null and not editable. Clicking the plus sign to get max $$$ also does nothing. Same for coins in Pokémon Blue.