Perhaps they're out there, but the only Win 70 H-S stocks I've seen or known of are those from Heavy Varmint and Laredo series, plus the Marksman custom series; maybe the earlier Stealth models. None were for short magnum or wssm if there is a receiver dimension difference between wsm & wssm.
What might work is an HS stock from a FN-Herstal Patrol or Police model. Those were chambered in .300 wsm, at least a few. Might also look at the Hogue overmolded with full alum bedding block and Bell & Carlson Medalist. A McMillan with factory installed pillars is also a fine solution...