[chasdev]

Depends on WHEN in 41 it was made.
I have an all matched 41DUV with a flat buttplate but it was made early in 41.
Later in 41 they switched to cupped...
If your serial number lacks a letter suffix then it would be SUPER early and therefore need a flat buttplate stock.

 

[chasdev]

My DUV41 has the serial number on the buttplate.