If you want to brink it up to date to be like the new ones you can.
Simply by a clam auger extension, and cut off the extension part right above where it is welded on. Then take and cut the screw top off of the old auger, and insert the top part you cut off from the clam extension. Then weld it on. Take the old handle and drill yourself the three adjustable screw holes in it. Handle will then insert in just like the new augers and be adjustable allowing you to use any of the new stuff like the drill plates & adaptors. I did it to an old 10in folding mora handle and couldn’t be happier.