Looking at the pics, the stock is toast, and the metal finish is shot as well. Collector value is minimal. Not non-existant, as all Savage 99s have some collector interest, but yours is in very poor condition.
A good friend of mine, and a 99 collector has one about like yours, with a bent barrel besides. He has had it refinished, and rebarreled with a .30-30 barrel. Its still being worked on, but the metal is done, and looks great. He knows it won't bring top dollar, but doesn't care. He just likes 99s, and has several.
.303 Savage (NOT the same as .303 British) was a very popular and common chambering for 99s of that vintage. The round went obsolete a long time ago, and ammo was non-existant for a long time. Today you can get it again (but it ain't cheap). I see a lot of .303 Savages at the larger gun shows in my area, as the original owners have passed on, and families are selling them. Ballistically, the .303 Savage (which uses common .308" bullets) is right on par with the .30-30 Win, although factory ammo was loaded with a 190gr bullet vs the .30-30's 170gr & 150gr.
You can get the stock replaced (repaired? doubtful, but ask an expert), and the metal refinished, and have a nice looking example of a vintage 99, worth some, but not as much as an unrepaired/refinished one. If that's your thing, cool. IF not, your best bet is to find a savage collector (not all are looking for high end pristine collectables) and see what they think.
I have been working with stocks since I was 17. To this day I have not found anything I could not fix. Including bent barrels and broken parts. I do full restorations as well. 
