Call Boyd's. https://www.boydsgunstocks.com/e
BTW, welcome to the forum.
The side of the receiver is stamped with the model designation. If you have the 'first edition' it should show the "Deerstalker" moniker, which adds some value, and subsequent guns bore a name change. I would not dispose of the original walnut stock too hastily. In fact, if your gun is a Deerstalker, and has not been altered, I'd seriously consider collector frenzy and find a different shooter.
For reference, the Deerstalker was Ruger's first rifle, introduced for sale in 1961 at what would be over $910 today ($108 in 1961). The RS model, Sporter, and International models followed. It requires jacketed bullets and the company loudly recommended only jacketed full-power factory loadings, due to the gas port in the bore and the relative difficulty of thoroughly cleaning lead deposits from the gas system (not to mention re-assembly). Ruger provides neither service nor parts for this gun today. In no small way, the 44 rifle or "Carbine" paved the way to all Ruger long guns.
don't be put off, ask any question here and you'll find myriad answers, most better than mine.
