I saw that 28 gauge for sale on Auction Arms.
I have the exact same shotgun and it has a fixed modified choke.
I've loaded it up with heavy shot loads and it shoots a lot tighter with a modern plastic shot wad.
I also load it with .520 caliber round balls, a .015 patch and about 50 grains of powder and it will hit bowling pins at 25-30 yards just about every time.
But those round ball groups will open way up at 50 yards.
It's a very light and fun shooting shotgun.
Oh yes, it also has tiny ears on the tang which serve as a rear sight groove which is somewhat unusual for a smoothbore.