After looking closely at Alan Shepard's training knife in the following photo, it's hard to tell, but I think he has it without scales as well. Perhaps taped?
Look at the close up of Shepard's knife and you see one of the bolt holes close to the end of the tang.
Here is a photo of Shepard's knife in the center, with my 2 Astros on each side in about the same angle. What do you think?