Find the part number for the grill on your tractor and then look at parts diagrams for other similar tractors to see if they share part numbers with yours. Messick's website is a good place to start...
When I was hunting a headlight assembly for my G1800, I discovered that the T-series mowing machines of that era and later also used the exact same assembly. [Ended up buying NOS at the dealership - only $90.]
-Paul