1952 saw the return of gold proof coins to the annual, so called, Long Proof set. Before that, only the 1923 South African Proof set contained the Sovereign and Half Sovereign. This is the only set that has King George VI's image on it's gold coins, other than the set from Great Britain of 1937, in all of the British Commonwealth.
The £1 Pound, or 20 Shillings (Sovereign) and £1/2 Pound, or 10 Shillings (Half Sovereign), have the exact dimensions of it's British counterparts.
The obverse of these coins were designed by Henry Paget (HP) and the reverse of the coins were designed by Coert Steynberg (CLS).