I would also be interested if someone has a link to a table that shows the serial number for H. Pieper's.
I have a 38 caliber falling block that I researched the snot out of a few years back.
H. Pieper was a gun maker in Belgium between the late 1860 up until his death in 1898. His son took over the business and kept it going until it went bankrupt maybe 15 or so years later.
I was told that since my rifle is marked H. Pieper that it was probably made "before" his death - later guns were just marked Pieper, Liege (etc).
It was suggested to me that checking the other proof marks would give me a better idea of the date and I would suggest the same to you. With the double shotguns there is also a way to identify the barrel (material).
With the barrels unhooked/removed there should be a stamp on the (floor) that will be a letter and two digits. The digits are the barrel length (28 or 30 or whatever in inches) the letter that precedes them is the material they were made from.
The codes I have notes on are: S = Steel, T = Twist, K = Krupp, D = Damascus and C = Chain Damascus. Not having a shotgun I didn't investigate the descriptions any further than that, simply kept what few notes I had scratched up on Pieper.
I could never find any correlation between serial numbers and year of manufacture anywhere.
Just about all of Pieper's guns were built for export and I did find that for my falling block there was numerous parts available particularly in the US, but given that the value of my model "restored" was somewhat under 200 bucks I didn't pursue it too far - but it does look cool
There should be a bunch of proof marks from the Liege proof house, that will at least tell you when it was proofed which should be relatively close to it's production date.
