ok the box outlined in red i pretty much recommend to just remove and or reuse for the components. notice the two arrows in yellow cut traces to ground and use two wires to flip this.
change the 33k to a 47k tie it to the gate of q3
the caps in purple would probably just be better to mount on top of the board. connect points z together. change 2M pot to a 20k
lost the original one due to some crazy windows seven error this was a fast and dirty redo hope it helps