Inspiration taken
from Avia Dejavu http://crimso.msk.ru/Site/Crafts/Craft20288.htm and http://www.airfighters.ru/zavaruhn.php
72 giap together with 28 giap and 68 giap belonged to the same 5 giad. Regimental marking of 72 giap (at least) in this time period was red propeller spinner and red band on the rear fuselage.
Full discussion is at http://massimotessitori.altervista.org/sovietwarplanes/board/index.php?PHPSESSID=5ceegbtocp1f2jfo4fn7sdn5i3&topic=1714.msg14342#msg14342