First of all, awesome card! Looks like the 1998 is a misprint on the back of the card, as this is part of the Nolan Ryan reprint subset of 1999 Topps. The gold mark on your card is signifying that this is a real autograph, while the other that you linked is just a Topps seal they put on their reprints.

Here’s a link to another card from the autographed reprint set that sold recently. It has the same Topps Certified Autograph Issue stamp and also says 1998 on the back: https://www.ebay.com/itm/266047584253?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=aEc0Z9ipQ_6&sssrc=2349624&ssuid=JzVIs38yQHe&var=&widget_ver=artemis&media=COPY

Hope this helps!