I guess I didn't think much of them because, as the years went by, so many great innovations have come about in this area. Still, I think there's merit in this approach.
This is incredibly lightweight. The balsa wood one weighs a few grams. They each weigh as much as a solid piece of the material they are carved from. Because the hinges are as large as the fingers' diameters, they are very study, so the fingers don't flex from side to side at the joints. Being solid means they resist compression fairly well.
There are few moving parts: just three finger segments, three axles, and two cables. No complex pulleys to deal with or the like.
A mechanical engineer might object to the friction that can come from the large hinges. I was worried about this when I build them but was surprised at how little friction there is. I may have put some powdered lubricant in the balsa one, but I put nothing in the plastic one.
Probably the greatest weakness of what I built is the cables. The balsa one's cables are made from bundles of sewing thread and the plastic one's are ordinary twine. I envisioned a production version being made from plastic and having cables made from thick fishing wire. I imagine this could easily be made from aluminum or another metal and use steel cables.
One other shortcoming is that the cable runs are exposed on the bottom when the finger is extended. Although they are very small slots, they still can be pinch points or places where dirt can collect and foul the machine. When I build these I imagined there would be a skin covering the mechanisms.
One nice thing about this design is that it lends itself well to sculpting. You can probably see that I whittled the outside of the balsa one to give it a human finger shape. It's unusually thin, but I expected I could have added more layers to fatten it out to human proportions. Although the diagram doesn't show this, the various layers have different diameters for the hinge parts to account for the curvature of the fingers.
Again, it's not much to speak of, but I thought it might be nice to post about this here. But it's also a reminder that I made this over half my life ago. So much time has passed and I really haven't done much of the research I had hoped I would in that time. It's a bit sad to think this modest creation might be the pinnacle of my creative efforts in robotics.