I too have this "special" 916a , it may look like s/s but is actually a "nickel" plated finish, and most have a gold colored trigger.
these were made at the end of this shotguns manufacturing run.
Mine is the riot model with extended magazine.
They are a very basic shotgun, not the best quality, but they worked and were cheap to buy, and most folks would never shoot them enough to know or care about their longevity.
I have seen them sold in as new condition to NIB for from $250. to $350 over the last couple of years.