The Silverstone car was in fact DBR2/1. For a closer look at both cars I suggest checking out my article on the car
http://www.ultimatecarpage.com/frame....php&carnum=18 , which shows recent pictures of DBR2/1 in the first six shots and DBR2/2 in the next six.
DBR2/2 was at the Historics again this year, so both cars are out in the open.