All the promotional material I had seen for Barrow Hill Live had mentioned that one of the visiting locomotives, which would be in steam, would be LNER B1 number 61264. I was a little confused therefore to see a B1 named Impala, number 61002, in steam. Not knowing how many B1 locomotives has been preserved, I just assumed it was a last minute change that hadn't been announced. It turns out though that the locomotive was 61264 just masquerading as Impala.
From a little bit of research the only surviving B1 locomotives are 61264 and 61306. A little further digging and I found that 61264 has been temporarily renumbered to 61002 as part of the 40th anniversary festival of the North Yorkshire Moors Railway. Apparently, prior to being scrapped, the real 61002 had pulled trains from Whitby to Grosmont, Pickering and beyond, along what is now the North Yorkshire Moors Railway. I'm assuming it will revert back to being 61264 next time it is painted.