Thank you, JenB. In these images it looks like a 'K' with a circle drawn round it.
On the page in your first link, the one in entry 51054 (col.2) seems to have it drawn fairly carefully with the circle drawn separately. In most of the others it looks as though the circle was drawn as a continuation of the 'K'.
I can't work out why some have it in col.2 and some in col.6; and in the second link, some have it in both.
