The pic shown from the auction is a cavalry carbine lacking the bayonet and mounting assembly. Your pic does not show quite enough to tell if it's also that model.
The rear sling bar recess appears to have been filled but you would be better able to tell that. Filling the recess used to be fairly common to make the carbine look "more sporty".
If you wouldn't mind posting a couple more overall pics and maybe another of the rear sling bar recess, someone here can quickly tell you.
I'm not sure about the apparent 'safety'... custom add on? SW