Hello ALL again. I wasn't able to find where that barrel band came from. Sent the one photo off to some collector friends to see what they can find.
Meantime I think I can add a little more here. The more I look at the photos the more I'm convinced it is one of those - shall we call it "re-manufactured" - guns from one of the Belgium gun factories sometime in the 1850's to 1860's.
I have read that the various hash marks (/// or \\\), Roman numerals, letters, even complete numbers somewhat haphazardly stamped on the stocks, were in part so the various components could be later identified during final assembly, as many components were actually fitted to new wood stocks. So you could end up with a pistol (or musket) with a Belgium barrel, English lock, and French hardware - all assembled to a new stock. LOL That's why it can be so difficult to ID these guns.
This was not a small one on one buying of parts. A Belgium factory would buy another government's complete inventory of surplus parts. They would then build/rebuild complete guns for resale to the civilian markets all over Europe, Africa, and even North America. And even today, they do show up everywhere.
Belgium was a prolific gun making center. And this reuse of surplus parts must have been profitable since it seemed to go on for some 20+ years.
Here is a good example of these repurposed guns: I believe this is another one of these Belgium pistols. It has a late English flintlock pistol lock with barrel and components from - who knows where - assembled to a simple, newer made 1850ish stock style. The barrel band is held with a pin on just one side if the stock - all assembled in the simplest manner possible. You can see the "hash marks" in the lock mortice area.
Rick