Howdy! VAMs are easily searchable on this site: http://vamworld.com/wiki/Morgan_VAMs_by_Date Including the one you're asking about: http://vamworld.com/wiki/1898-O_VAM-17
No problem - enjoy! It's very comprehensive and thorough. I sometimes have a hard time getting started. Meaning - if I have a Morgan dollar without something obvious (like a die crack or a prominent doubling), it's sometimes hard to sift through dozens of VAMs for a given year to find a match.