Marlin 39A - POI a foot off from POA

Hello all, I have a Marlin 39A that I purchased NIB about a year ago. Barrel is marked New Haven Conn.

I have had the rifle out to shoot on several occasions and had lackluster results every time.

Today, I shot it again, about 30 yards distance to the target. I fired from a bench and sandbag rest. My shots consistently hit 8-12" LEFT from my POA. I drifted my rear sight to the RIGHT to compensate. Didn't make a difference. Drifted it so far it was more than halfway out of the dovetail.

Finally, put a laser boresight in it. According to the laser, I drifted my rear sight back to dead center to match POA with the laser. Fired again, still 8-12" LEFT POI. Had my Dad shoot it also in case it was just me - he had the same results.

What gives? There is no damage to the barrel or crown. I am totally stumped, and thoroughly disappointed. I could try to send it back to Remington/Marlin I guess, I just can't fathom what would even be wrong with it to make this happen??

Any advice would be appreciated.