Baldwin's completed its much anticipated auction of British Coins, World Coins, Military and Commemorative Medals in London last week with over 11,000 coins going under the hammer.

As expected the top lot was an exceptionally rare Matt Proof Finish Gold Set of four coins dated 1937, consisting of Five-Pounds, Two-Pounds, Sovereign and Half-Sovereign, struck for photographic purposes at the Royal Mint.

Each coin depicts the bare head portrait of King George VI facing left, engraved by T Humphrey Paget, (a tiny hp appears below) and the legend in abbreviated Latin reads georgivs vi d: g: br: omn: rex f: d: ind: imp: and translates as "George VI, King of all the Britains, Defender of the Faith, Emperor of India.

On the reverse, the King's saintly namesake is slaying the dragon.

Near unique... the George VI coin set

The matt finish is a very surprising feature, as a letter which accompanied the lot explains. It was written October 4, 1961 signed by Chief Clerk H G Stride of the Royal Mint, written to Douglas Liddell, latterly Managing Director of Spink:

"Dear Mr Liddell

"We have examined the set of George VI coins and we are satisfied they [sic] they were given the matt finish before issue by the Mint. The matt finish is given to each coin individually by very fine sand-blasting and as the process is very laborious it would not be practicable to apply the treatment on any but a very limited scale.

"None of the 5,500 sets made available to the Public was treated in this way and it must be assumed that your set was specially prepared for a particular occasion of which a record no longer exists."

The set is one of just two known in private hands, which naturally makes it a strong investment, and sold as expected for £90,000 ($147,300).