Well, its an 1896 action, carefully inletted into an 1898 rifle stock. The sight is an 1896 sight, correctly mounted, cannot tell if it is a carbine sight though. The front sight looks added on, though very well done, the base should be slightly set into the barrel, without the dab of solder visible on the side. Though that might be an armoury repair of an original carbine.
An excellent starting point to any of the carbine models, cavalry, engineer, or even a school/constabulary carbine, with all that forend to play with.
I fear though, that bidding is going to get stupid on this one.