Battara and Rick,
Thank you for your interest and comments. I have compared the blade to a piece of red brass and an old piece of copper and the blade looks most likely to be made of copper. This seems to be a strange combination of materials to make a dagger from unless steel was at a premium or not available at the time it was made.
If it stops raining for a few minutes I will take new pictures. Should the brass and copper be polished or just cleaned with ren wax and a soft cloth?
Robert