How to tell which Petrucci has SS frets?

[tildeslash]

I've heard about a certain type of bridge was used when they switched over to SS frets.

 

[dave1812]

The old Trem had a cutout on the High E String Side, basically shaped like a Strat Trem.
The newer Trem has a rectangular Baseplate with no cutouts and the SS Frets came roughly at the same time as the new Baseplate