hi mate, what size seat did you end up getting. I have just been looking at this problem tonight. I have a Century SS and have tried fitting my 25mm ABU reel seat. its to tight to get on butt. I have measured butt and it is 25mm so I am going to try and get a 26.1mm ABU tomorrow. The rod had a 28mm seat fitted, this was packed out with tape.I don,t like using tape, also if you want to change seat position you have to have tape in different positions.