I beleive this is caused by rocks cracking it and water getting into it. Mine is doing the same thing. IIRC the dealer wanted like $50 for a replacement. I was just going to get one off of ebay, they are about half that on there.
Somewhere around 99 Ford changed the emblems, from then till about 03 you can boil the emblem to soften the clear and peal it out then you use acetone to take the blue out. In 04 they changed them again and they have a different type of clear in them and boiling them doesn't work anymore. The clear on them will come out with the acetone but its hard removing it and you have to polish them to bring the chrome back up after you do get it out (thats why I said his would probably clean easier) You can check your sizes also my 86 has a tailgate emblem off a 03 in the grille there the same size.
Thanks for the chrome idea. Mine looked like the one in the first post and I hated the look. I really did not want to spend $50 only to have to replace it again the next time a rock hit it. I did boil the emblem and it made it a lot easier to pull of the clear but it still was a pain to get it all off. I worked on it for about 2 hours and my finger tips are killing me. Once I got all of the clear off, I rubbed the blue off with acetone. It came off EASY with the acetone. After it was completely clean, I polished it with a turtle wax chrome and aluminum polish. It came out great but I will have to see how I like it in the daylight tomorrow. Here are some pics.
How the heck is your front grille so clean with no rock chips! Our's looks like it's been through a sand blaster. I love / hate the painted front. It looks great, but chips so bad and the underlayer of black is so obvious.