If you look on the back of the amp you will see 2 master volume pots.
They are PPIMV types and the first one you can set for your rhythm playing as normal and the 2nd you can set higher that you can kick in via a footswitch for leads. Won't be needing my Keeley SD-1 anymore.
Just a thought, couldn't you have run a MXR Micro Amp or some other booster in the loop for lead boost??
Click on my soundclick for some clips.