Gary, that is a beautiful gun!

I checked my 12 gauge #1219 front action lifter and it appears that it has the “PB” in the shield as well. I posted a picture below. Most people on this forum would know more about this than me(though I am slowly learning), I just wanted share that a gun made close to the same time has similar stamps.

That gun is very nice to say the least, I hope you enjoy it!

Jay