Brent,
That is a very nice gun, but would suggest later than 1830's.
Very few back action were made at that time.
The engraving on the gun in the O.P I take as original.
It is very typical of good quality work.
As Feltwad says, it is a Birmingham gun, and many were made and engraved with a retailer's name.
The retailer could choose what and how he wanted the gun engraved and finished.
If he chose higher end work, he could have it. The cost was more, but he could get what he wanted .
A great amount of English guns were not made by the person it is marked to.
This is how the gun trade worked and still does!
Best,
R.