IMHO - Model date does not influence value, if a Krag receiver has been drilled & tapped.

Model 1898 and model 1899 receivers are identical, except for the date.
Model 1899 receivers were intended to be carbines. Some carbines exist with receivers marked 1898 over-stamped 1899.

Some rifles exist with model 1899 marked receivers; there is uncertainty about the manufacture, (why, when, or who).

Measuring your barrel length from muzzle/crown to closed bolt-face, exactly, with a cleaning rod is a good clue to possible origin. A carbine barrel will be exactly 22 inches.

If a short barrel is even a fraction longer than 22 inches, it is a "cut-down" rifle barrel.

If I understand correctly, "Blocks" is a reference to the occasional periods, when Armory production was devoted to manufacturing a batch of carbines.

Krags were not manufactured in numerical order. Finished/numbered receivers went into parts bins to be randomly pulled for assembly.
Model 1898 and model 1899 serial numbers can intermix to some extent.
(Likely, the model-date 'stamp' was put on at a different time then serial number 'stamp').

Rifle stocks were not used to make model 1899 carbine stocks near the end of production.

In the mid-1920's, Benicia Arsenal was shortening Krag rifles for NRA member sales. These were cut to carbine length, put in a carbine stock, and fitted with 1903 Springfield front-sights. When the supply of carbine stocks was exhausted, rifle stocks cut to carbine length, were utilized. (BTW - I don't think your Krag is one of these "NRA/DCM carbines).