The refrigerator vent cover is cracked on my 1977 Argosy motorhome.
The vent we need is available at Inland RV. It is part #84000
Inland RV vent (stamped aluminum)
28" L x 8.5" W x 4" H
My Argosy MH Fridge vent cover (made of some sort of plastic)
24" L x 9" W x 4.5" H
Andy's website page says to seal the old holes with rivets before installing the larger vent cover evenly over the existing vent.