Sorry, but that serial number is WAY out of whack to be an original 1898 carbine. Barring the extremely unlikely case where it was an "official" repair, at some unknown point in time, the gun was apparently assembled outside the control of SA.

The stock appears to be a correct carbine stock, albeit of M1899 (32") form, and the rear sight appears to be a genuine M1896C - all good points. Original 30" M1898C stocks are very scarce, if not rare. The rear sight is, as stated, quite valuable on its' own.

As it sits, it would have to be evaluated as an M1899 carbine. It is in very nice shape, and if the bore is good should be a really fun shooter.