==Help for Victoria!== 
 I suppose it reads this with the correct spelling: 
 '80 CTS CORREO AEREO MEXICO' 

 This means the price of 80 cents (about 0.03 pounds), "air mail, Mexico" 

 'Valleres De Impresión De Estampillas Y Valores-México'  

 I don't exactly know the meaning of "valleres" but I think that's the place where the stamps are printed, it literally would read "printing workshops of stamps and values-Mexico". I hope I shine a little light on that matter ;)  

 PS: and is not Mexican, is Spanish! "Mexican" names the Nahuatl language spoken before the 16th century in Tenochtitlan. You can see the Keane article in Nahuatl here: ! ;)