You're looking at the wrong spot for FS-501. The example images of FS-501 you posted a few minutes ago shows the remnants of a repunched D to the southwest. THAT is the RPM, not the bit on the right side of the mintmark. The appearance of doubling on the right side of the example image is damage and on your coin is Machine Doubling.
Disclaimer: While a tremendous amount of effort goes into ensuring the accuracy of the information contained in this site, Coin Community assumes no liability for errors. Copyright 2005 - 2026 Coin Community Family- all rights reserved worldwide. Use of any images or content on this website without prior written permission of Coin Community or the original lender is strictly prohibited. Contact Us | Advertise Here | Privacy Policy / Terms of Use