Joab said:One armed men were generally exempt from the prohibitions on switchblade carry
The ban was so obviously flawed it barely got any support at all and with all the vets from WWI and WWII they didn't want to anger amputees by not creating an exemption for them. Remember that the only way you could open a "jack knife" at the time was to use the nail nick or your teeth if you didn't have a "springer".
Folks like me that collect switchblades were very aware that the AWB was just a gun version of the switchblade ban. We were amazed that the gun community didn't take the AWB more seriously in it's earliest rumblings when gun folks just didn't believe anyone in their right mind would ban certain guns based on their appearance. The parallels were obvious to us but there was no significant organized group to oppose the legislation and legislators during the 50's. Now things like the WSJ tactical knife article shows that the same mindless fear mongering is still in the inventory. Pitty that the silly laws on auto knives didn't sunset like the AWB.