You need to go to the Congressional Medal of Honor Society for the correct answer and if no answer is posted, submit your inquiry directly to them:
My own review shows that the MOH citation reflects the individual’s rank at the time of the action for which the award is being given. The individual wears his current uniform and rank when it is presented.
See thse articles on MOH receipient LTC Bruce P. Crandall, who was Major Crandall at the time of the action. He retired as a Lieutenant Colonel.
http://www.cmohs.org/recipient-detail/3250/crandall-bruce-p.php
https://www.army.mil/medalofhonor/crandall/
Thank you GreyFriar...I just sent the MOH Society my question.
I want to talk more with you about the photos you posted, but I have to leave home for a couple of hours.
Thanks again!
You are 100% on the money, GreyFriar...I posted the response from the MOH Society...#28.
Thanks for helping me out.