I've posted before on this subject.
At this point, it is strong speculation that PHS or (someone else) has data that matches the VIN to the engine number. My guess is at some point, "they" stopped providing the data when "they" realized it could easily be used to "create" a numbers matching car.
If this info is being held back, it's good and bad for us.
For example, I feel 99% sure my car has the original engine. If I had the "info" we're talking about, I could sure without a doubt.
Dan
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