Think I need to rephrase what I'm asking... I'm trying to figure out a way to convert a Fsm Game Object into a Fsm Owner Default. 
private FsmOwnerDefault parentGameObject;
private FsmGameObject childGameObject;
// This dies because childGameObject is not a FsmOwnerDefault. 
// I'm not sure how else to assign targetObject to childGameObject 
// w/o using GetOwnerDefaultTarget.	
var targetObject = Fsm.GetOwnerDefaultTarget(childGameObject);
storeComponent.Value = targetObject.GetComponent(storeComponent.ObjectType);
(What I'm actually trying to do is create an action that changes the icon attached to an NGUI button. To do this, I have to reference the parent button game object, then drop down to the child icon game object, then grab a script object that controls which bitmap is displayed for the icon.)
I've attached a WIP of the script. It's about half written (or copied/pasted from GetChild & SetProperty)