Cream butter and gradually work in the fresh citrus rind. Add the sugar and cream together until pale, light and fluffy. Place raisins, currants, sultanas and mixed peel in a bowl. Sift flour and salt together twice and add 50g of it to the mixed fruit. Mix well to cover all. Add the ground almonds to the butter and sugar and mix well, then gradually add the eggs one at a time, beating well after each addition. Gradually fold in half the remaining flour, then the fruit little by little. Fold in the rest of the flour. (At this point add the alcohol if using it) Spoon the mixture into greased and lined cake tin and smooth the surface using the back of a the spoon, briefly soak the almonds in the milk and arrange close together in neat circles on top of the cake Bake at 170 C for 45 minutes then continue cooking until done. Lower the oven temperature to 160 C/ 130 C fan and cook for a further 60 minutes. Check after 50 minutes