Photo of the headstamp would help.

Were it mine, I would shoot it through my LE without any concern, all of them.

However, I wouldn't do any fast shooting, rather aimed shots. Sometimes the 'click' and the 'whoom' just as you lift your head, or just the click. That ammo is 60 years old now, and you should expect a hang fire every now and then. Were it me I would shoot all of them as time allows me to.