Hi Dennys thanks for the further pictures.

I would suggest it is an M36 dagger in an M33 scabbard as the centre ridge on the reverse of the blade appears crisp and quite level suggesting it has not been ground.
Has the dagger been appart? If so are the crossguards stamped on the inside and are there any markings on the tang?

Best wishes,
Ian

www.simplydaggers.co.uk

www.germandaggerscrews.co.uk