Looks like a stripped and modded chinese stock or a USGI birch.
I can't see the numbers in the top pic
If there is just a serial number and no other markings, it is a pre2005 import.
Import info started appearing in 05 thru 07.
With. the vast majority, if not ALL of the components for these rifles were manufactured in the late 80's early 90's.
Not sure how you would find actual import info of a pre 2005 unless it has an AL before the serial numbers indicating allan lever of the original lever arms.
Under the stock, on left side of receiver will have a set of loosley punched numbers. These can be forwarded to forum member "Different" for info on receiver manufacture dates ect.
EE prices of 400-450??? Where are those LOL
Seems 500 to 600 is the going rate for a good condition gremlin free usgi stocked chinese m14 these days.