The symbols are proof marks from when the gun was proof fired with an overload at the proof house prior to being sold. There should be others than the ones you posted. A vies of all of them would help us a lot in identifying it possibly dating it. Since you didn't mention it, is it safe to assume you didn't get the scope which was once fitted to its claw mount bases, or even the mounts.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra