Thanks for the feedback from the pros!
I guess there is some consolation in knowing that my speculation is correct and that my knowledge of these engines is growing.
I am thinking that if this valve hit, others may have also and I may need to pull the left bank of heads as well. I know that a leak-down may be an indicator but the only way to be sure that the rest of the heads are good is to remove, inspect, and measure. Do you agree?
Thanks again!