What you have is a typical English half stocked fowling piece circa about 1810 by Henry Holmes .My records show that he was in business in 1804 at 12, Castle Street, and moved to 55 Paradise Street 1806-1811,then to 12, Castle Street 1812 -1830. His next move was to 88 Lord Street 1821- 1825, and finally to 1 Harrington Street 1826-1837.
His son also called Henry and a gun maker began at 9 Parker Street in 1831.
I would say that your piece was converted to percussion at a later date because it is fitted with a percussion breech plug and not the standard way of a drum and nipple .You do not give the bore size but I would say it is a 12 or 14 which is big for a flinter most are 20 .
One question I must ask is there a name on the lock plate because it was common to fit another barrel to an existing gun thus the barrel with a percussion breech plug , there is a possibility that only the barrel is by Henry Holmes and the rest by a unknown maker
Feltwad
