Almost right Mike Jenvey, but you forgot the very first thing in such a scenario, and that's to make the right callout:
0. Utter an appropriate expletive, for example:
oh 
what the
religious deity of your choice
1. Identify the problem.
2. Confirm the problem - both pilots.
3. Handling pilot would instruct non-handling pilot to carry out appropriate emergency or abnormal check-list action - monitored/confirmed by handling pilot.
I agree with everything else
Under these SOP's though the before takeoff checklist must include "PA....OFF"