The current Imperial State Crown is a replacement made by Garrard in 1937 (ed 1837) and altered in 1953.
According to The Crown Jewels 1998, the history is recorded on a plaque mounted over the back of the Black Prince's Ruby -
Rundell Bridge & Co, Jewellers to Queen Victoria, 28th June 1838 Partly remade by Garrard & Co, 1902 and 1932 Entirely remounted for Coronation of King George VI, 12th May 1937, by Garrard & Co Remodelled and partly remounted for Coronation of Queen Elizabeth II by Goldsmiths & Silversmiths Co Ltd 2nd June 1955
Edit: adding pic
--Previous Message-- : Yes that is correct. : I quote from The Crown Jewels by Anna Keay : "By 1937 the state crown made for Queen : Victoria was a hundred years old and in a : sorry condition. The frame had been : gradually collapsing over the decades, : shored up by various repairs. So weakened : had it become that as it travelled to : Westminster Hall on George V's coffin, the : top cross containing St Edward's Sapphire : jolted off. The procession had marched on : but fortunately the Company Sergeant major : of the Grenadier Guards, seeing what had : happened scooped the cross up as he passed : and dropped it into his pocket." : "It was clear therefore that the crown : would have to be completely remade for the : coronation. The new frame created by Garrard : was essentially a replica of Queen : Victoria's crown, though the jewellers : managed to reduce the overall weight by 283 : grams" :