Strad:  My 1899 Krag Carbine, #349187, was probably built in September 1901.  It likely carried a Cartouche dated 1901, when it left Springfield Arsenal.  When I obtained it, it was a 'deer rifle' in a modified Krag rifle stock.  The action and barrel were great and not ruined.  I was fortunate to obtain original carbine parts and return my 1899 to its original configuration.  I was glad to have a nice 1899 style "long for-end" carbine stock without a Cartouche, rather than a stock with the wrong Cartouche.  Your 1898 Carbine is quite nice.  There are not a lot of 1898 Carbines.  I imagine most were updated to 1899 pattern and have the "long for-end" stock, without Cartouche.  (ps - It would be interesting to see a photo of the base of your carbine rear sight showing the Spring attachment).