G'Day Rito,
that's a classic rifle, I'd be putting a match barrel on it in either 221 fireball, 204Ruger, 222, 223 (maybe a 1:8"T for F class and up to 80gn bullets) Dont worry about larger diameter cartridges as this will lead to you needing different magazines, mofication to stock, possible ejection issues etc. Leave the bolt face alone and use ANY case with the same diameter as the .222. and this makes for a painless easy conversion for you AND the gunsmith!
If you want a larger case like the 22-250 buy a suitable action with a burnt out 22-250, 243 or 308 etc. All the hardware you need will be there for a basic rebuild...saves $$$$$ too.
As for the stock follow the link to SSAA articles hints & tips for fixing up old stocks, it really is quite simple, Birchwood Casey Tru-Oil is a good finishing product, search this forum and you should find topics covering this too.
http://www.ssaa.org.au/stories/hints-ti ... shing.html
The web has PLENTY of sites covering stock re-finishing especially some of the shot gun sites
Hope this helps
Cheerio Ned