So the date on this ticket is 1940..
Actually, the Irish Hospital Sweepstakes began in 1930. They have a charter from the Irish government as a trust charity, which was re-newed in 1940. As stated above, your ticket is from 1952, for the Cambridgeshire, one of 4 annual races that were used for the sweepstakes. (the others being the Derby, Grand National and Cesarewitch). In the mid-60's, as the international popularity of the IHS declined due to the increase of local lotteries, other races were added, including the Lincoln and the Irish Sweeps Derby (later just the Irish Derby).
I have just recently dug out my collection of these, and am starting to scan them to develop an on-line display.