I have solved my own conundrum. Anglian 462 started life at Metrobus with fleet number 538 which explains the identification marks but doesn't explain why they are still there!! Anyway here she is in her Metrobus colours at Showbus no less in 2004. Pic by Ian Roberts on Flickr whose extremely varied photostream you can find here.
|Anglian 462 looking brilliant in her original Metrobus colours at Showbus 2004. Pic by Ian Roberts|