From 1922:
Cut 3 lb. of pie melon in small pieces and cover with vinegar; let stand all night. Put on to boil with 3 lb. of onions, 2 cupfuls sugar, 1 dessertspoonful of salt, 1 teaspoonful mixed spice, 1 dessertspoonful cloves, ¼ teaspoonful of cayenne popper. Boil for two hours, then mix with cold vinegar 1 tablespoonful of mustard, 1 tablespoonful of turmeric (light color preferred), ½ cupful of golden syrup and boil a little longer.