Rare Cretaceous Ammonite Fossil Aulocostephanus?

Offered for sale here is a very rare ammonite. 

Found on the Holderness coast as an erratic nodule.

The ammonite shown in the pictures is the exact one you will receive. Not 100% on the ID but I was told it's a Aulocostephanus species.

125-145 million years old

Hornsea Beach

Cretaceous, Holderness coast, North Yorkshire