1990 United Kingdom Proof Collection in the "Deluxe Red leather" Case. In December 1987 the chancellor of the Exchequer announced the intention to introduce smaller and lighter 5p and 10p coins, The first of the new coins, the 5p, was issued in 1990 and the Decimal Proof Set of 1990 contained the last of the original 5p decimal coin, and the first of the new coin. The £1 coin represented Wales in 1990 and was the second in the floral series. In 1990, no 50p or 10p coins were issued for general circulation, making this Proof set a must-have.