Alfsmum

[ Hi there Just wondered if anyone could help me identify a coin i came across the other day It is gold in colour on one side it shows a standing man and a seated woman holding a baby in front of a large building the sky above the building is in bright shiney gold, the rest is in what i would call brushed effect gold. On the reverse it says 30th November 1874, born at Blenheim Palace the first son of Lord Randolph Churchill and Jennie Jerome around this in what ooks like a sash/belt design are the words Honi Soit Qui Mal Y Pense . At the top of this is a lion holding a sceptre along the edge of the coin are the words Trustees presentation edition a number and what looks like some tiny hallmarks does anyone know what this is please? and what its worth ? Really appreciate anyones help thanks size="3"]