Benelli B76 Impact Damage

I recently purchased a used but still nice Benelli B76 for my collection. I have put probably around 100 rounds through it or so, but during the last range session, the slide began sticking and became very tight to work at a given point. I took it apart and discovered that the locking shoulder in the frame appears to have been peened out of shape by recoil impact, and is thereby pinching the bolt and jamming the action.

I have searched around and havent seen this as a problem listed anywhere else for these guns. It seems that that shoulder should be well enough hardened to handle recoil, and the gun appears to have been used, and the ammo I have doesnt seem particularly stout... it is an early 1979 serial number of 11xx, if that matters.

Does anyone have any experience with this happening to their B76? Any ideas other than peening it back smooth and setting it on a shelf until I can find gunsmith with a clue how to fix it?

I only have a sample size of one but the priming weight is fairly light compared to other guns, presumably by merit of there being little in the way of locking peices. My understanding of the mechanism is that the lever wedges against the slide and pushes the bolt down into the locking surface in the frame until enough recoil energy has bled into the slide for it to begin moving, which then allows the bolt to slip out of lock and be drawn rearward. In that case it seems to me that a light spring would result in the slide moving sooner, and less recoil force overall being directed into the frame... but then again, the entire thing is a bit of a complex physics equation...