Welcome to the Forum! The star stamp is a fitter's/assemblers mark. While it's not all that rare to find an occasional S&W with no serial number visible on the butt, my guess would be that your gun's butt number was polished off, and the grips refitted to the gun. The picture of the left side of the gun shows that considerable buffing took place before the gun was refinished, probably years ago. If you do a magnaflux Xray of the butt, it will probably indicate the metal's molecues were disturbed by the original but number stamping, and maybe even make the number readable. Ed . #15