Here is a dha from Vandoo's collection (kindly donated to the Dha Research Index).  Though it has an unconventional handle, the blade is not atypical.  It has a copper plug near the tip as well.  I have no idea of the significance.
The recycling theory makes some sense, assuming the blade was made by stock removal.  If it was forged, I would think that at the very least the pre-existing hole would be distorted.
http://members.cox.net/thedhapage/C0021.htm