I'm sure he probably can, but it is such a nice original 16 ga. that I really hate to do anything to it as drastic as tubes, even permanent ones. But, I would really use it a lot more if it had some choke.
And, with a tapered choke which is smaller at the muzzle than the bore you have the problem of sizing your card wads too small when they pass through the constriction. Then, they are loose in the bore and no good. With a jug choke, however, the muzzle is no smaller than the bore diameter. You just enlarge the bore for a short stretch, then it comes back down to bore diameter. The card wads are not downsized then, they stay bore size.
I've read V M Starr, and he had m/l guns choked that would throw 80% patterns with both barrels. I suppose the limiting factor is wall thickness, but if you consider that .015" choke only reduces wall thickness by .0075", you should be able to improve on a gun's range considerably by jug choking, given that it has ample wall thickness. And, there's not much pressure left for the barrels to contain out there.