Ditchbanker, you would get more attention, and help, with a new thread.
Since you posted here though.....
Your ribbed barrels can have the Williams open sights added. They fit right on the rib. Get them on solid then bench test sundry "Rifled" and Brenekke slugs until a clear winner shows.Zero, then buy plenty of those from the same lot and go hunting.
I too have a background in hunting with a longbow. Hunt the same way with your shotgun.
Here in MD, doing so with various 870s kept the freezer filled nicely.
HTH....