Captain Kangaroo did enlist in the Marines.. but did so too late to see any action during WWII. Signed up several weeks after the fighting at Iwo Jima.
Lee Marvin did see action. was wounded and did receive a Purple Heart. Not a Navy Cross. and he was wounded at Saipan not Iwo Jima.
Would have been a fun story.. but no dice
I wasn't sure about Captain Kangaroo.. But as soon as I read this thing, I knew Mr. Rogers was no navy seal LOL