Here is a link to some old posts & many different opinions. This will open a can of worms from a light clean to a BLOscrub to a ruined stock... Think preserving original patina...
Stock cleaning advice needed 9 nov 2014 repost - Surplus Rifle Forum - www.surplusrifleforum.org
oil scrub stock cleaning - Surplus Rifle Forum - www.surplusrifleforum.org
Most surplus stock are best kept as found.
Lets see a picture of some stock sections and a close up of the worst section???
I might just suggest a light application of ..."Howards orange oil ( NOT LEMON OIL ) or Kotton Klenser brand "Protective Wood feeder".
Please see the many references and methods used by others.