GM,
We almost let you get by with:
"IIRC, ETO Mustangs did not have a wire antenna going from the cockpit to the tail. Only MTO and PTO ones did. Can anybody confirm/infirm?"
After wading through all my Mustang stuff, I agree with your observation. I can confirm use in MTO and PTO, but no evidence of use in ETO. Now, are you going to tell us why?? Icing, or what? I have a 4th FG P-51D pilot friend and will see if he can remember.
Always something to learn here
