Agree with tcsned. You probably will not get great Jerry tone from the Classic 30. I liked my Classic 30 but it broke up on the power side, near as I could tell. I replaced the preamp tubes and got extra headroom at the cost of some of the "grainy gain". I put a 5751 in the V1 position and a balanced 12AT7 in the phase inverter, the V3 position. This seemed to add clarity and some headroom to the preamp section especially on the clean channel but I did lose what I surmised was annoying, lower volume, power tube breakup.
I also hear that upgrading the stock speaker in the Classic 30 is one of the most straightforward mods to make to "improve" the tone of the amp. I never did this but numerous others I have spoken with have done this.
The river keeps a talkin'