Congrats. Looks like you made a nice purchase if the price was not unreasonable. Your M1899 was made Sept 1899 with the stock cartouche matching. This is an early M1899 in the first grouping of M1899 carbines. The stock having some wear and refinish is not significant for everything else being good. The M1901c rear sight had a higher front sight blade than earlier carbines. Usually the front sight blade has the "c" stamped high enough so you can see it. I can't tell on yours because of scratches. Might be there.

The bolt is the correct bolt for this carbine also. Some of the carbines and rifles in this age range had the headless cocking piece. But it's sort of hit or miss on these.

I see a repair in the front of the hand guard. Be careful removing that. Looks unstable and might need cleaned up and re-glued at some point.

Is there an oiler and cleaning rods in the butt stock?

How's the bore? If you have a good bore, that's really a keeper!

But looks great! Welcome to the Krag carbine owner's club!