I found a picture of an original Astro where the screwdriver was clearly shown, and made a copy of it out of brass. (I used brass not because it is easy to shape, but because it would not harm the machine screws holding the scales on the tang.) It works well; I filed the blade area so it would fit exactly into the screw slots. I'd be concerned that I would harm the screws with a steel screwdriver. Here's a picture...