Here is Google AI's information on DDR SKS, or Karabiner-S.
Markings: The receivers typically feature a two-digit year of manufacture followed by a letter prefix (documented letters include A, E, F, L, N, and U) and a four-digit serial number. Rear sights are often marked with the letters "SV."
Stock Material: They were typically issued with laminated wood stocks.
I'm not sure if this stock is connected to the DDR.