7578 I found out today is actually a loan ?... as there is a white a4 piece of paper stuck on the door side window stating that it is on loan from Arriva Northumbria Ltd to Arriva Durham County Ltd. Also I passed 7579 as well and glanced over and also saw a white piece of paper so I assume that said the same thing. Also looking at Flickr it seems 7580 has some paper on it too so they all seem to be loaned not actually transferred. Strange as I thought they were transferred…