Even if it is less than perfect, your weapon has survived for a century in working order, which is probably more than will be said about you when you're 100. 1884 rifles will frequently have 1873 breechblocks and be passed off as the older weapon. The cartouche on the left side of the stock will have the actual date of manufacture which can also be deduced from the serial number. Rifles without cartouche or proof mark have less value regardless of condition. Krags are very rare and can cost several thousand.
Markings are the same as on the Trapdoor rifles and the same concerns apply.
Carbines in both Krags and Trapdoor rifles cost more since fewer were made. These were well made but have no historical value, however some dealers will overprice them. Many carbines were made from cut-down rifles or assembled from parts. Many krag rifles were cut-down in the 1920's and some of these are also passed off as carbines and overpriced. When in doubt check the serial number.