you'll always regret loosing the vent wings, just go drive a 73+ mop with out AC... they are very effective at moving air where you need it...
now if your still stuck on the idea i ditching them i would pick up a 73 dart swinger door with all the internals. from there you can modify (cut to length and adjust mounting/adjusting tabs) and then maybe have the glass cut or limited for travel if not to long...