Captured British tanks were even on Red Square in Moscow, as this amazing clip from Russian TV shows.
In Swedes at War there is a page about Swedish volunteers in the Russian Civil War working in close cooperation with British tanks. One of those tanks is still around, in Arkhangelsk. It was recently restored and there is now even a book about it.
The tank in question, now even has a very detailed Wikipedia-page. The above clip from Russian TV describes the restoration process and also has some amazing footage from the Russian Civil War era.
As you can see from the Wikipedia page the tank is now inside a protective structure. When I visited tank Mk V No. 9303 some years ago it was out in the open. Still, it was not in a poor state, not at all. So, I was quite surprised by the thorough restoration, which must have been costly.
I was also pleasantly surprised the other day when a friend lent me this book about this particular tank: