Hi daan!
Welcome to the Knife Network!
While it's not easy to draw a conclusion from one photo, I don't think the handle is ivory. The grain appears to be more like Westinghouse Micarta, which yellows with age and eventually was referred to as "Old Yeller Micarta. Try googling this and you'll find a wealth of information about this material.
The knife itself (which is a beauty) is a Model No. 12-6". It is called a "Little Bear Bowie".
Hope this helps.
Cheers!
David