My wife brought in a keyboard she suspected was defunct and asked me if I would look at it. I did.
The keys work better now.
To do this, I popped them out of the keyboard housing, ground down the posts flush with the bottom of the key, and adhered some tie tacks and small pin findings to the back with some E6000.
One of the challenges with the project is the grinding; if you grind the key surface too thin, it makes a little dimple on the surface of the key.
Still, I have a number of them that turned out all right. My beautiful wife has taken to wearing a Shift key on occasion. I think the F1 Help key would be a wonderful fashion accessory for a technical writer.
The cost of each materials is about 35 cents each for the tie tack, a drop of glue, and the portion of a keyboard. Not too much. But I doubt all keys would be interesting to people.