Western Ware Double Cloud Rarity??

I have an 16" by 9 1/2" Monterrey Western Ware Made in Mexico platter with a double cloud above the chuck wagon scene. Does anyone know anything about this line of enamelware from the 1960's? Is the double cloud an oddity or are all the 16" platters done this way? I love it and had planned to start collecting plates for our new camper but they seem to be quite collectable and therefore costly and one seller noted the double cloud was rare. Any information would be helpful. Thank-you!