As I thought, no real usefulness, sort of like Tyler grip adapters, but many like the looks. We all have different tastes in what we look at and there's nothing wrong with that.
This is a copy that I built of a USMC Remington 870 Mk 1. These were made in the late 1960's for the Corps. An original one sold for $16,000 at auction a couple of years ago. It will take a bayonet. I used this one to teach a Combat Shotgun Course to the Navy when I was stationed at Naval Station Long Beach.