A response from Heritage Auctions on the Bradshaw helmet.....

Thank you for your inquiry. As any vintage helmet expert will tell you, face mask clips become incredibly brittle over time, and eventual breakage is all but assured. Such was the case with the Bradshaw helmet, and when the original black clips were broken, our consignor replaced them with clear clips. This is how we received the helmet, and how it was originally imaged for the auction. At the time of consignment, he asked if we could locate some original period black clips for the helmet, which we did. The helmet was then re-imaged with the black clips. Both images remained on our site and this seems to have caused some confusion. Rest assured that there is only one Bradshaw helmet, and that it now features the rare and proper period clips.
Just to be clear, the original Dan Marino game worn helmet face mask clips were broken as well. It was consigned with clear clips (as it is imaged in the catalog), then upon locating the proper period clips, they were exchanged. The online images (www.HA.com) feature the vintage replacement clips. Please let me know if you have any additional questions or if I can be of any further assistance.
Regards,
Jonathan Scheier

Sounds plausible too me as I have had vintage helmets and the clips do break easily....