your diet and training seem ok, but i think the problem here is probably portion sizes. instead of having 'a baked potato and some salad' with some tuna, have 2 cans of tuna, 2 or 3 baked potatos, and a big bowl of salad.
isntead of a chicken sandwich, have 2 chicken sandwiches, etc.
your aiming to shoot 500 - 1000 calories above your maintenence level, which for your weight is probably around 2250 calories - 2500.
it might be a good idea also to have 2 myoplex shakes a day. you want to aim for 6 + meals a day.
"What do you normaly eat "
when bulking up for breakfast it would be my morning breakfast shake (1000+calories) - you can see recipe here:
http://musclechat.co.uk/viewtopic.php?t=2813
then 2 hours later 2 flapjacks, then for lunch something substantial like 2 cans of tuna with 150 grams pasta, 530pm pre-workout i have 1 1/2 scoops whey with some oats in water, after workout 1 scoop whey in milk, while i prepare a big meal for about 45 minutes later, perhaps 3 chicken breasts, 200grams pasta, some ham, and lots of brown bread.
before bed i would normally have some egg whites and then another protein shake, this time with milk and some peanut butter (no carbs).
nick