I do not know who Henry is but I like the keep it simple approach.
That's a beautiful smooth bore, and a VERY interesting thimble,.... any idea as to who the made the gun?
Here are a couple of pictures of a later era shotgun with the thimbles soldered directly to the underside of the barrel,......
I'm trying to figure out if J. Henry normally soldered the thimbles to the underside of the single barrel shotguns he made,... or if something happened to the gun's under rib during its history of use and somebody did a quick repair by soldering the thimbles to the barrel.
You can see the ramrod has a bit of a "bow" as it enters the stock, causing me to question if this was the way J. Henry normally built his shotguns.
The lack of an under rib puts this little 20 bore in the 5 1/2 lb. range, and is a pure delight to carry and shoulder for someone with torn rotator cuffs.