Documenting a restoration properly serves three purposes: it helps you during the project, it establishes provenance for insurance and resale, and it's genuinely interesting as a historical record.

The minimum documentation standard: photograph every panel before disassembly with a reference scale and documentation of any markings visible. Photograph the undercarriage, the engine compartment, and the interior before any work begins. Save every part you remove, at least until the project is done.

Beyond minimum: maintain a parts log showing every sourced component — part number, supplier, price, date, and any relevant notes about authenticity or quality. Create a time log showing actual hours spent. The time log is sobering and useful.

The documentation itself becomes a valued part of the car. A buyer who can see photographs of the bare metal before paint, the frame before restoration, and the engine before rebuild has evidence that the story told about the car is accurate.