I'm sorry, but I am going to need you to clarify exactly what you are referring to and what you mean when you say Cullinan Rough Diamonds.
The Cullinan that I know was the largest rough Diamond ever found, weighing in at 3,106 Carat. Also, and until very recently, the the Cullinan 1 was the world's largest polished Diamond, weighing in at 530 Carat and forming part of the British Crown Jewels.
Please can you clarify exactly what you mean and exactly what you are trying to sell. I am currently under the impression that you actually mean that you are looking to sell rough, uncut Diamonds?