From what I've found from researching these particular mustangs is they belong to the 319th FS.
Aircraft No. 73 is USAAF S/N 42-103443, Plane Name: Margaret, Pilots: Edwin L. Williams (1 Kill in a Mustang) and Howard F. Welch. Salvaged 9-2-45.
Aircraft No. 87 is USAAF S/N 43-24852, Plane Name: Gravel Gertie/Delightful Dee, Pilot: Jack H. Bond (4 Kills in a Mustang). MIA 10-12-44.