Yup it's a fine line - for instance https://www.trademe.co.nz/a/marketplace/antiques-collectables/militaria/swords/listing/4440056804 it's even called "Awesome Tribal Ethnic Type Dagger Knife Fighting Weapon Short Sword" seems normal but trying to sell a 1970's riot baton is considered restricted. I'd hate to be th one making these decisions.    

Thanks Callum - Seems crazy - I'm more likely to look to a softball bat as weapon versus an antique Edwardian police truncheon. Thanks for you help.