Looks like there might be a third beanley portable stone - the mystery deepens :-) Link below show's Tate's 1865 drawing of this one.

http://rockartuk.fotopic.net/p30665285.html

Looks like it might be one from you?? as the full title is Tate, 1860s
beanley-c..1860s.tate.06.hob.47247.jpg - spot the hob?

Tate's description of this is that it was a loose stone found while draining a field west of beanley. He doesn't say it went to Alnwick Castle (which he does with another).

Only concern here is that the form looks identical to stone B but the shape of the stone and the position on the form looks totally different - so it could be an artists view of B rather than another portable?

Thats' me done on this one, off to browse google earth for another target :-)