Replacement by VIN build sheets is not available for U.S.-built Mustangs. Those were considered internal documents and were not part of the invoicing side of Ford. So it becomes even more of a problem with Mexican-built vehicles. Unless you can verify with another Mexican Mustang owner, there are no accurate ways to ascertain what type of system the Ford La Vila plant used or if they even used build sheets similar to U.S.-built cars. Marti reports will also not be available on any Mexican-built Mustang as these were "Knock Down" kits. Meaning incomplete vehicle shells with no powertrain and did not have a Vin. The Marti reports are derived from info on the Ford invoice (AKA Lois Eminger). The invoice contained retail and dealer cost of the base price, options, freight, and other accounting numbers the dealer needed for their accounting system. Since these "Shells" were not built as a complete vehicle in the U.S. and were assigned a Vin when completed in Mexico, they are not in the Ford U.S. database.
Mexico had some robust content laws on the percentage of Mexican supplied components of vehicles manufactured there.
The engine, transmission, and differential were manufactured and supplied to the Ford La Villa plant from local Mexican manufacturing plants. The 351W engine and transmissions were Mexican-built, but the differential was a Dana unit since Ford did not manufacture 8 or 9" differentials in Mexico. None of these particular Mexican-built engine/drivetrain components were used in any U.S.-built 71-3 Mustang, so none of the codes would be the same as used here.
Others here may have more detailed info on these cars. I have some limited Vin and component info but not much else. I have tried for years to obtain some Mexican parts manuals on these cars but have been unsuccessful.