Thanks for the referral Joe. This material...on this knife is cataloged as Ivorite micarta. It is not of the same properties as the Westinghouse material other than some of the production processes. It remains white and does not darken (yellow if you will). I am posting a #24 to my website, right now, with the same handle material and it appears to be linen-based but could be paper, although the "grain" looks like fabric to me.
Hope this helps, Capt. Chris
PS: On a knife, coming standard with a leather handle, (which your's is) the Ivorite is an upcharge (2020 pricing) of $60.00...CCS