I have four European flintlock fowlers; one each of England, France, Belgium, and Germany (converted to percussion).
Here is the English one: 16 ga, 33 3/8" barrel, 49" loa. The inside of the lock is marked "TM" which someone told me was
likely Thomas Moxham of Birmingham who traded from 1799 to his death at age 75 in 1837. This was likely a cheap export
gun and I am surprised that it has survived so well.
Birmingham proof marks
All the best
Paul