Unfortunately I can't help with the Delta AR Top Gun and Benelli pistols. I know them but I don't have any documentation. I've never seen a Delta in person. I've seen some Benelli B80 .30 Luger and B82 9x18 Ultra at my LGS for very cheap prices because of the obsolete calibers.Honestly, many of my Itailian pistols are a mystery to me.
I've got Delta Top Guns, Bernardelli race guns, Benellis, rare Berettas, etc.
I once had the occasion to shoot a Bernardelli VB Practical in excellent conditions with two barrels with different muzzle brakes to choose for. Nice shooting pistol. The owner bought it used for €350 which is the price for a used Glock with some wear.
I have some old italian gun magazine reviews of Bernardelli pistols if you are interested. The problem is the same: they are written in italian...