Third Reich sheath knife I.D. please

I was given this knife shortly after WWII and have never seen another like it. It is a work knife and not fancy. The sheath is heavy leather and well made. Overall the length is 10". There is a high relief Swastika on the butt of the aluminum grip. The handle is one piece aluminum with a cross guard and stippled grip on both sides. The blade with fuller on one side, is 5 5/8" long. The widest spot on the blade is 1 5/16". The blade is similar to a Bowie type, with the edge being on one side only and a clip in the back, dropping down to meet the tip.
The full makers code is hard to make out. The part that I can read, looks like "EP668". The sheath had a strap through a slot, which closed on a brass stud. The strap is not present. The sheath appears to be of high quality leather, but unmarked.
I can send photos to anyone who may be able to ID this knife for me.
Best,
Steven A.