Dennis,
Looks like white lineal micarta to me. White lineal micarta was used by the shop for a very short period of time. It fell between the disastrous "white crap" that the shop tried as a replacement for Old Yeller. That stuff checked up and there are more than a few knives out there that show these faults. I recently re-handled a Bear Bowie-#12-8" because of it and that has already been shown on this forum (BMK did the handle/ Amy the sheath).
Lineal micarta was replaced by AGM and the Model #10-3", shown below, is the only example I have of it in my STASH. Rare? Probably. Scarce? For sure! Hope this helps, Capt. Chris
PS: It isn't as yellow, in real life, as it looks but it has yellowed over time...CCS
Best, Capt. Chris