Have 1896 Krag Carbine. Where did stock come from?

Serial is 70301. stock is very good fit, has rounded cutout for bolt handle, looks like matches age and patina of carbine. has long front end, high hump wood handguard, 1901 sights "C" marked. only marking is letter behind trigger guard. Looks like arsenal stock.
is it?

Your carbine was upgraded to the M1899 carbine configuration. The M1901C sight, the high hump handguard, and the long stock ( w/o the sling ring ) were probably added at the same time. I have one very similar to yours.