I would appreciate seeing pictures of this Indiana rifle. Very little is known about this late gunmaker. The only reference to him and his gunmaking is found in the 1870 Indiana census, where his name is given as E. R. Hamilton, residing in Monroe County and working in Bloomington. I have never seen one of his rifles, despite seeing and handling many Indiana muzzle loaders, and would enjoy seeing what this one looks like.
I am a little amazed at the length of the barrel on the "rifle" you describe, at 49 inches, particularly for a gun made by a late maker when barrels were generally shorter at 40 inches or less. Often a longer barrel gun with large, smooth bore indicates the gun is a fowler, or single barrel shotgun, rather than a rifle. Such guns often lack a cheekpiece on the back of the butt, have no rear sight, and the trigger guard lacks a grip rail behind the bow section as rifles have. Can you post pictures here, so we can all see the gun? If not, I'd still enjoy seeing them at sgallien@comcast.net and will be glad to repost with an opinion on exactly what you have. I will ask a couple of other Indiana collectors to see if they have any additional information on Mr. Hamilton. Shelby Gallien, Indiana