I was finally able to talk to the gunsmith and get some better information. Apparently, the cocking cams don't always engage the tumbler, causing the firing pins to stick against the primers when the action is opened. The gunsmith's initial assessment was that someone had previously worked on the cocking cams and had not done a quality job.
He did go on to say however that the top lever was slighly left of center and that there was some small but perceptible movement in the barrels when the fore-end was removed. He said he would not call it "off-face", but it was close. The dealer is going to repair the cocking cams and make a more detailed assessment of the gun's condition.
Sorry for causing a lot of speculation. The gun is 50+ years old and is set up like a pigeon gun (30" barrels, tight chokes, 7.5 lbs), which would suggest the possibility of high-volume shooting.
