Not Taking Pictures Before Disassembly
This is the digital age where taking pictures has never been easier or cheaper. Jeff Lilly suggests rounding up a good digital camera and a 2-3 gigabyte flashcard to photograph the entire disassembly process. And if you inherited a mess, attend a Mustang show or two and photograph how the best restorations are put together. Images, coupled with the Jim Osborn Assembly Manuals mentioned earlier, will get you on the right path.