A B4 at York in 1935 isn't that unusual, more likely working in from Lincoln in the late 30s. However after checking 6101's allocations, it's a Copley Hill locomotive. I'm trying to work out why it would have turned up at York. Neville Hill supplied locos towards the North East I thought. The photo appears to be the North End of York Station, is she coming off shed?
My only thought is Doncaster have borrowed it for a local working. Or was there a regular turn for Copley Hill locos?
Thoughts gents?