This is a WW2 USGI replacement stock that had been shellacked:
https://www.milsurps.com/images/impo...b225333g-1.jpg
I stripped it with Formby's furniture stripper (rubbing with 0000 steel wool), then applied Formby's tung oil (3 coats, rubbing with 0000 after each coat, including the final coat).
With all the dings & possible oil/grease stains, yours might look better if you apply dark stain after you strip it. Hard to tell at this point.
Neal