This item has been denounced in the Angola 2000 UPU Circular number 406 as illegally produced without the authorization of the postal administration. In the circular it is described as "Personalities of the 20th Century" but the values are wrong. In the Sn catalog it is described "in general" as Great Personalities.
Produced by the British counterfeit producer and still being distributed by associated counterfeit stamp dealers to this day. BEWARE of fake First Day Covers and color proofs. Avoid sellers of these!