Hello. Wanted to get information on a Rogue  that I'm thinking of buying. Owner had some trouble with the serial # and isn't sure if it is 98Q11609 or 98Q11689. Any help would be appreciated. Thanks.

Welcome, Bob.

I tried to complete the research on the bass you were interested in. Both serial numbers resolve to Epic basses with serial number codes of W so while it's certainly possible we're dealing with a duplicate serial number, I also cannot locate a file with either of the numbers you provided.  
 
Sorry - and also sorry this request took so long for me to research for you.