[rotorwrench]

If the frame is not badly corrosion pitted, stampings can be brought up using the correct forensic procedures. The steel has a more dense grain in the outline of the original stamping imprint much like a forging process. This allows for it to be forensically identified even if it was sanded down. Police agencies use the procedure to identify weapons that have has the serial numbers removed. Certain acids will react more quickly to the softer surface that has not been imprinted than it will to the imprint which raises and restores the stamped characters. I'm not sure what acid it favored though.

I generally try a pencil rubbing first. It will somtimes bring out the unseen parts of a stamped character. Few model A bodies have a VIN/seriel number unless it was added. Some bodies have a body number but not near all of them do. It just depends on when and by what branch or subcontractor built it.