With the lock configuration, how the stock looks to step down at each barrel band, I think this is an 1853 pattern 3 band Enfield. Or it started life that way. It looks a lot like the rifled muskets used in the American Civil War. There was no bayonet attachment, it used a socket bayonet that locked on the front sight. Here's a link to one that wasn't used quite as hard as yours. If you have a magnifying glass and some time, maybe there might be some faint markings left to find.
Three Band Enfield Musket - Live Firearms and Shotguns
The socket for the bayonet looked like this