Luftwaffe Friday Afternoon Puzzler

I bought this as an unknown.

All I know is that it came from Oranienburg in Berlin and was claimed to be from the Heinkel plant.

The plant produced He111, He177, Ju88, FW190, V1’s and Do335

It has several diamond stamps on the reverse with what looks like 2 over 8K or 8H and 14 underneath.

I assume it is a lower wing access panel. There appears to be traces of white and either green or black paint on the outside and possibly some insignia/code painted on it.

No part number – some very faint black paint that may once have said something.

It has been used.

Any confirmations…..