Just picked this axe up. Taken it apart to look under the hood etc. What's the number mean on the back of the neck (2.) before the EX T? After taking out the set screws on the volume and tone controls, the knobs don't want to come off. Frozen? Something I don't know about with these basses? 4 ply tort pickguard. Any one see one of those before? Thanks for the answers/info.