It is sometimes a wrong position but
when someone comes to me with a problem and tries to make it my problem, I usually say no. He sold his Dad's carbine, he has a problem. Now he's passing it on to you to solve for him. It may not even be true. Admittedly it isn't much of a big deal as both guns are not GI, but he may just have made himself another problem by buying an AO, and now has two problems for you to solve for him. I would do whatever is best for you and not him, selfish? Maybe, but you just bought a gun, not some guy's problem or his life story.