Well, I'm not sure he did.... I think the Flying Scotsman comment got him confused cus he said "In which case it can't be the Flying Scotsman. I can't magnify them enough to read their numbers clearly but they are different and both could be LNER A4 Pacifics. The stripped down one looks like 4468 - The Mallard" Tbf - dad is 88 years old now & sometimes gets the wrong end of the stick.
After a little techno panic, his phone battery needed a recharge, me Dad finally figured it out after a little prompting.... And as this is the random picture thread, this is what you get when you google 'the mallard in green'