try googling images for 'ebay bronze arrow points'. i see a zillion of them just like those up for auction. some turned into brooches, some still looking like they were just cast, some with a nice deep green patina. here's a newish one with much the same point defect as the one on the left of your middle photo.
the roman bronze reproduction market is quite extensive. i know a guy who is casting modern ones in iron and another guy who does them in bronze for re-enactor groups. i have an archer friend that uses the iron ones for traditional bow hunting.
in other words, caveat emptor.