Hi Andy great pictures, the last one shows a pair of Goldfinches, cock on the right hen on the left,you can sex these by looking at the red 'blaze' the cocks goes behind the eye the hens doesn't. As for encouraging Bullfinches they like to feed on fruit tree buds, the Orchard owners hate them! You could try a good quality British Finch mix not the rubbish wild bird food which is full of cheap filling corn etc. try searching for suppliers of Haiths, Beyers or Country Wide Seeds.