K98k with mismatched stock - likely history and value?

[kar98k]

Is there any way to tell manufacturer and date range of the stock, based on the markings, shape of the buttplate etc? .

one of your pictures shows the right side of the butt stock. on it is an eagle over "H" showing it was issued to das Heer (the army). below that is Waffenamt 655. WaA655 is a waffenamt attributed to Mauserwerke Oberndorf from 1938 through 1941. flat buttplates (as yours has) were the norm until late 1940 when cupped buttplates appeared in large numbers. your stock appears to be solid wood and not laminated beech. laminated stocks didn't show up in large numbers until 1939. it's reasonable to assume your stock was made anywhere from 1938 to 1940.