Thanks again to all. I've learned a lot today!
1) Buy a new (or used) 24" smooth bore barrel with rifle sights.
2) Put my 18.5" barrel on G/B to re-coup some of the cost.
I just ordered a tactical collapsible stock for my shotgun. I have the full wood furniture for it along with the 28" vented rib "goose barrel". A while ago I put a pistol grip on it with the 18.5" barrel. While it looks badazz and it's real easy to stow, I don't care for it as it's difficult to handle, and after a couple of rounds it does a number on my hands. Looking forward to extending the barrel another 6" and setting her up with a shoulderable stock.
Thanks.