Also consider:
A small magnifying glass, multielement screw together barrel not a "detective" style, handy for close look at connector pins etc.
A small but strong flashlight (the new LED ones are great) to help look deep into things.
A stick and some double sided sticky tape to retrieve small parts from deep inside of things. (Not all screws are magnetic).
A camera to document where everything was before you started.
BTW: I not an A&E, my only aircraft HW experience is helping my brother in law with his light sport, but the above will prove handy in almost any field.
I suspect most work will be either swapping boxes or finding faults with and fixing cables and connectors, comments from those who do?