Where can i buy Salted Mackerel (Salt Cured)?

My Grandfather said that when he was younger they would buy a wooden box full of mackerel covered in salt for preservation. I searched the internet and didn't really find it for sale... I found some Mackerel in a tin of oil (like sardines) but that's not what I am looking for. I am not looking to buy in bulk, just looking to buy some for gift for "Pappy"