I think the project is cool, but since a usb snes controller is, what 5$ on ebay (or more to have quality one), I find it too bad that you damage a working, vintage real snes controller that there will be less and less of.
The way I saw it, I'd rather have a memento of the past that I can actually use than one that will sit around in a drawer.
With an adapter you still can use the controller (or you can also use a snes)