Noticed it a few times now, but no idea if it is the same vehicle (too busy looking at the blind, rather than id).Pretty sure they all display Arnison Centre in capitals.
The ex London Presidents on the 14, have Arnison Centre in capital letters, rather than the usual 'via' format of lower case.
It could just be the one vehicle, which I am seeing repeatedly, or a few have been done.
I think they are in capital letters on the Lolyne's too.