1966 L72 427 Biscayne questions

[kenbrogan]

I recently purchased a very nice 1966 Biscayne that is suspected to be an L72, The car has all of the date correct component's with matching casting numbers that would represent it to be a real L72. This includes the engine block, heads, bell housing, intake, carb, transmission, tail shaft housing, starter, alternator, rear end housing, along with radio delete, heater delete, 7k tach and more.

My only concerns are that the VIN plate in the driver door pilar and the protecto plate have 15311 yet the cowl tag uses the 15411. I have researched and found that this could happen if the vin plate and protecto plate was produced prior to changes made with options during the ordering timeline?

I appreciate any feedback, I want to fully understand this car.