Original M14 stocks are worth some money. Can go over $300 for an original wood (pretty shortly, in service, they replaced wood with fiberglas which are themselves worth over $150!), but like collector stuff, small differences and proof of it (provenance, or marks) makes all the difference.
Do some searching about types, look real closely for marks, etc. Hopefully someone will come along who is an expert and can tell you if birch or walnut, that sort of basic stuff to help the search.
Do NOT take any serious steps to clean it up. Again, collector value, will likely be cleaned in the end etc but don't want to risk damaging anything, the finish can help identify the age and type, etc.
Start here:
https://www.m14forum.com/threads/usgi-m14-wood-stock-identification.91006/
If you don't have good hollow ground screwdrivers, etc, then get some or have a friend help to make sure buttplate removal doesn't damage the screws, plate, or wood.