Bravo, here's a thread with a good explanation of the differences. High/wood low wood refers to the amount of wood covering the operating slide on the right side of the stock I-Cut refers to the slot for the oiler in the buttstock. Early carbines had a "I: cut, i.e the cutout resembles a capital "I" with flared out ends. Later oiler cuts were oval at the ends.
https://www.milsurps.com/showthread.php?t=21200