Of course you looked at the chassisplate so we know what bus this is? You were standing only two meters from it :)

Unfortunately, I was not officially. He did not want to attract attention of, so go carefully and photographed little.
Now, very sorry about this. But on the other hand, it is good that there is at least the photos.

Now find out what it was for the bus is almost impossible.
He may not have worked on the route, and immediately was the donor.
Two buses are numbered:
http://fotobus.msk.ru/photo/580104/
http://fotobus.msk.ru/photo/580103/

In a few buses I was looking for numbers, but there was no.