'Blacksmith' - Your Krag is a real model 1896 carbine.

As you stated, it has issues. These mainly involve the cracked refinished stock, other wood damage, and the missing hand-guard.

I do not know the condition of the bore. Most of the exterior metal finish is gone.

Your carbine appears to have its original sights. The model 1896 carbine rear-sight is worth around $400-$500, by itself.

IMHO - Your Krag carbine is worth around $850 in its current state. This is mainly 'parts value'. It is a poor candidate for 'restoration'.

(p.s. It is very difficult and expensive to obtain original Krag stocks and hand-guards. An original carbine 'sling/bar & ring' is a $75 item).

I am sorry about the loss of your Brother-in-law.