Jim,
You're almost there, just lose those Full chokes (which I'm sure it has) and go with cylinder on the right barrel, modified on the left and you'll have one helluva preserve bird gun, or wild bird gun if you're a good shot. Oh ya, make certain its chambered for 3" shells, if it's not I'd just have the forcing cones extended about 1.5"s (I'll loan you my .410 forcing cone reamer).
Steve


Approach life like you do a yellow light - RUN IT! (Gail T.)