I actually looked at large pictures of the original grip when making it but decided I wanted something a bit larger to mold into my hand. So you have to take it off to get the winder on.
I have a winder 2 and I agree that it adds on a nice hefty gripping area. But I like a smaller and lighter setup when walking around. As I tried in the past using a winder without batteries too lol.
Might be a nice side business to make camera grip 1 replicas lol with those crazy prices. Not sure if they are going to users or collectors out there.
Also there is another material called surgu which is silicone based. It's a bit more pricey. I think it could be used in combination with instamorph to make a softer grip area.