You can fix it and it is pretty easy. Check out frost fighter at http://www.frostfighter.com/ they have a little bottle and you can piant the grid back on. I had the same problem in my 81 and it fixed it perfectly. Just make sure to tape the lines off straight. A steady hand helps too. If you paint them on crooked use a razor blade to clean the line up.
Check with your local autoparts dealers, most sell repair grid tape. its the same stuff that is on the window now and being in tape form, it is easy to keep a even uniformed look to match the grid. This tape can also be used to repair printed curcuit boards that have been burnt due to shorts. I have even repaired boards on television sets that have been hit by lightning :laughing: