Lucky you, Guy. We got eight Black Rocks last week at auction - not for a tenner, though.
CGAH, Black Rocks are great hens - they're hardy, reliable and lay well. And they are lovely with beetle black plumage, with green and blue through it.
My favourite hen so far was a Brown Leghorn - she laid white eggs, occasionally and all over the place; she was totally bonkers and absolutely lovely. She died earlier this year - we'd had her about 4 or 5 years. She had a broken wing but it didn't stop her getting on top of the greenhouse!
We've also got Light Sussex and Rhode Island Reds, which are "proper" farmyard hens! The LS look like Lady Cluck in Disney's Robin Hood - plump ladies with big white bloomers!