In my search, I managed to rule out some false positives by decoding the barcode affixed to the vin tags. For example, some that had scuffed up serial numbers, or auctions that had listings with no serial number, I would take the image of the vin tag, and with basic editing, pass this in to a decoder to see if the stated VIN matched the serialized barcode.
For example:
Produces
Skid Steer Detective 