LCFox,
Indeed your gun sounds quite nice. If it's vintage 1927 or so it will not fall into this research project. The double barrel trap package I am researching was offered from 1920 or so up to 1925 and then it was eliminated. It was eliminated in the sense that you could then buy guns off the shelf that came standard with what was once special order options available when one ordered the Double barrel trap package.
The recoil reducers sure sound aftermarket, and I would think your correct in thinking the gun was set up for someone who shot quite a bit. Would make for an interesting gun to view...how about posting some pictures of the gun here?