FIRST, KORINA IS A FINISH, LIMBA IS A WOOD, A KORINA FINISH IS USALLY APPLIED TO A PIECE OF LIMBA WOOD
A 1976 Explorer is mahogany unless it was special ordered made from Limba.
The Epiphone V's Explorers and Modernes are made from bleached mahogany and other woods (lots of times it is northeren ash), with a korina stain. I have had a few rants about the "Korina" Epi's, do a search if you want more info
Even the 70's Ibanez V's Explorers and Modernes were made from bleached Mahogany and or Ash.
The supply of real limba is going away fast, (Just ask Evan, he got the story from Jol Danzig of Hamer)...if you want a real Limba Explorer I suggest a Hamer or an 80's Gibson 58 reissue...remember Korina is just a finish, if you ask for a Korina Explorer you leave yourself wide open for almost anything, if you look hard you can fina an 80's 58 reissue (the serial number will be stamped in black ink and it will be a letter (either A,B,C,D or E...maybe an F) followed by 3 numbers. Those are from the first set of 58 reissues, they did around 1500 V's less than 1000 Explorers and 143 Modernes (I know all this because I have one of the Modernes and I did lots of research)...good luck with your hunt