I have a 20 gauge 28" barreled BSS sidelock which I would never touch. First there are very few of them and adding choke tubes or even changing choke size would effect the value of the gun in a major way. Second, for some reason, I shoot it so well I find it no handicap. I have no idea why it works so well for me. It is not the only gun that fits me.
I bought a Remington SPR 20g. (Baikal) for rainy days with 26" barrels partly because it was so cheap. For some reason it also is deadly on targets. I know it is a disposable gun but it should last long enough to pay for itself on bad days. It came with mod and full changeable chokes. I bought skeet and IC chokes for it since I am near a skeet range. The scores were the same.
I was in South Dakota shooting pheasants and we came out of the corn into a weed patch in the field. Several pheasants rose and my body just lifted the gun and fired. No thinking was involved. It was about 30 feet away and my modified choke and 12g. #5's just about cut the bird in half. Chuck H. was to my right and he said he saw the blood come out the back like a TV movie shot. This was an Ithaca 37 and Mike Orlen is now putting changeable chokes in it.
My advice for Duff would be shoot it and then evaluate what to do with the gun.
