Westinghouse micarta first showed up on a trial basis it seems in the early 70's wit few 7 spacer examples floating around. The hey day was probably the think center spacer era from around 76 the 84, with the material used and Tune said into maybe the late 80's, and does come with the bonus of a Johnson sheath. Kinda the last of an era.

If you had two knives of the same model and options in both materials, I would say the Westinghouse knife would bring more easily, particularly to somewhat knowledgeable collectors.

AGM was tantamount to a "pre-aged" replacement for the Westinghouse material, in that it had a more orange color as the old Westinghouse material would sometimes get with age and/or exposure.

Note also, that the Westinghouse micarta was able to be scrimshawed, I don't know if AGM was ever scrimmed by Rick. Cap or someone might know the answer to that.

Here is a photo of an extremely rare model 14 with Westinghouse micarta that is relatively "fresh".