Most after market stocks take a lot of effort to fit properly, if you are a stickler for fit. They are oversized and need to be filed/sanded down to be flush with the metal. If you can do that and like it, or if you aren't picky about fit, go for it. Another option is to get a stock guy to repair the forearm, if possible.

“The Savage 99 Pocket Reference”.
All models and variations of 1895’s, 1899’s and 99’s covered.
Also dates, checkering, engraving.. Find at www.savagelevers.com