If you want a genuine SS button, it will cost you a lot (see above) plus $150 or more to have the repair made. And, the repair will be visible to a knowledgeable person. A intact grip from another dagger will be very hard to find as grips break more than blades ... plus it would have to be fitted.

A reproduction rune button is $25 - $50. Using one of those + repairs = $200 or a bit more.

Your dagger is not in top collectible shape. The blade has been sharpened an has traces of rust so beware of putting too much into it.

Hope this helps,
Dave