unknown muzzleloader

Question

Unknown Muzzleloader  

Numbers - Letters   Hello, I have been trying to identify this muzzleloader and find out its age.  Any help you could give would be appreciated.  This came from my wife's 95 year old grandmother, I believe her husband had hunted with it.  I'm FAR from being a gun expert, but I think it's a percussion cap muzzleloader, not a flintlock.  There are some letters or numbers punched into the metal near the hammer area.  It's not clear, but it looks like "I&W HENRY"  or "18W HENRY".  It may not be either one of those, but it definitely says "HENRY".

Hopefully you can figure out my mystery or at least point me in the right direction.
         Thank you.

Answer
Hello Eric.
   I have done a bit more research on your rifle and have found a couple of facts that may help you find your answer. The patch box, having a wooden top, is in the style of the Germanic Jaeger rifle. There were some British military rifles, built between 1830-1838, that were used during the Napoleonic Wars. These had this type patch box. They were in .75 caliber. Charles Gage