Paint delete code 1001 PA

[GNT]

I was looking at a 70 Nova that I might buy and the documentation said the paint code was a 1001PA.The firewall tag had 2 lines were the paint code usually is with no numbers.The owner was not sure but was told that it was a paint delete code were a customer could get a car in primer or another corporate colour not listed for that vehicle.The Nova was a light Le Mans type blue that I had never seen on a Nova before.He said it was the colour they found under the trim when the car was painted but it was not a listed optional paint for that car.Anyone ever heard of this.
Thanks.