* Dashboard: Underneath the dash, on the firewall, or on the dash itself.
* Driver's side door post: Look near the hinges or latch mechanism.
* Frame: Check various areas of the frame, particularly near the front or the firewall. This is often the most challenging area due to rust and difficult accessibility.
* Engine block: While less common, some manufacturers stamped numbers on the engine block itself.
You'll need to carefully inspect these areas, possibly using a wire brush or other cleaning tools to remove dirt and rust. A flashlight and possibly a mirror to reach awkward angles will be very helpful. A photograph or a detailed description of any numbers found will assist in deciphering the vehicle's original information. Keep in mind that the stamping may be faint or partially missing.
Remember that the number you find won't be a 17-digit VIN like modern cars; it will be a shorter, less standardized identification. It's often a combination of letters and numbers that will help identify the year, model, and sometimes even the production sequence of the vehicle. Online resources and Ford enthusiast forums may help you interpret the markings once found.