Temper this advice with that it is based off a pre-64 that I have.
On mine, if you push the safety forward, or forget to lock it in position before the bolt is disassembled, you get to figure out how to get a grip on the firing pin so you can essentially re-#### it, that you can set the safety lever to the hold position again.
That'd be my direction to take a look at.
You are going to have to figure out how to hold it securely and compress the firing pin spring, so you can lock it back using the safety.
Not broken, just missed a step in the dis assembly process or knocked the lever forward at the wrong time and allowed the firing pin to let down it's spring tension.
Cheers
Trev