Had the head off today and found marks on all the pistons! The marks are quite obviously from when the timing jumped 2 years ago as the car has had nothing done except the log book services. So I called ford and told them what had been discovered and they said that the valves couldn't have been bent as they did a compression check. After a heated discussion I ended up down there, which didn't achieve much,. but at least they said they would send the details on to ford and see what they say. I have attached a pic (note it is not the relief cuts on the pistons but the small indents opposite them)