Good evening Flychamps. Just an opinion from the peanut gallery. That looks to be an original center-fire gun. If it is 1866 that is very early for a center-fire shotgun. The center-fire cap shotgun shells had just almost simultaneous been patented in 1866 in March in the USA by Berdan and a few months later in UK by Boxer. (Interesting that the Berdan patent is now used in Europe and Boxer in the USA).
There are almost no original extant centerfire shotguns I've been able to find before 1866 (and I'll surely be proven wrong in this - nothing is sure in the gun business). So with the pistol grip and weight, wondering if your Lang might originally have been a small bore center-fire rifle converted to a shotgun when Woodward rebarreled it? For curiosity. . .what are the barrel lengths? (Standard UK shotgun barrel lengths for this period of time was 30"...which of course varied). This statistic would only be relevant if the barrels were rebored and not replaced.
My Lang letters as being a 16 bore "breach loading centre fire hammer gun" with 29" barrels weighing 2# 3oz. The replacement barrels are 27" and weigh 2# 12.4oz, 9.4oz more than the originals, so the original barrels must have been struck pretty thin. The rib of the replacement barrels is engraved "James Woodward" and in 1872 he added "& Sons" to the company name so the replacement barrels are from around 1872 or earlier.
Also, I believe that Daw introduced the French designed center fire shotshell to the UK in 1861.
If you want to look at the gun I'll have it at the Vintage Cup next week and can be reached at 803 530 5380.
