I have an old Italian 16 SxS, a tad over 6 1/2 lbs, decent engraving on the stock and steel. The best shotgun I ever had as far as feel and swinging it to the shoulder. Just falls in place like it should. The 16 is probably too perfect a gauge since it encompasses almost 12 and 20 gauge parameters. Sounds dumb but that's what I think.
The only other 2 calibers should be a .410 and a 10 gauge.. Just load the 16 up or down as needed.