Unfortunately, they do not sell just the stock, but FightLite has a classic Winchester 700-looking lower/stock assembly that they use in their SCR available by itself. It comes with their proprietary bolt carrier group designed to work with the angled buffer tube within the stock.
https://fightlite.com/collections/scr-lower-receiver-assembly-kits
https://fightlite.com/collections/scr-lower-receiver-assembly-kits