Welcome to the forum - Irons have moved on somewhat since the 57s came out (around 2008 iirc?) - They were Mizunos first full cavity back iron with a head size 25% larger than their usual MP irons - With that in mind, I think you would be comfortable with the current MP-20 MMC or any of the JPX921 range - Fitting is the way to go these days to get the club & shaft that works best for YOU
Paul