The local story (in short) actually is: The director of the museum saw a documentary about a plane graveyard in Bahrain that was aired next to the Formula 1 race there. He saw the Buran in the background, contacted the relevant people and got one short after :).
http://en.wikipedia.org/wiki/OK-GLI
(BTW: living in Speyer is very cool for tech-freaks: every once in while, they bring in a new plane, or a submarine...)