Another R mystery mark

An unusual pottery piece I found last week

with an R in a circle

Hi, I also have a mystery Mark R in a circle impressed into the edge of items,  I have a sugar bowl, a teapot, and jug.
I would dearly love to know the background and who made these...  Help

My actual photo's of makers marks 'R' and of the teapot set is under this heading

Is this NZ Pottery and who would be the maker?

Is this Ray Rogers mark, I'm lookin in Alan Coates' Pottery marks book.   

Hmmm I have Alan's book and will check it out, but it doesn't look like Ray's work. It looks too clumsy. Ray was a perfectionist.

Definitely don't think that the above mark is Ray Rogers one. I've checked Alan Coates and it's the same as the one in the Potters Marks book and also the one on our site. We will have to get a better mark of Ray's for the Gallery one of these days....

Lindsay155 says that this mark was made by Roger Campbell. I can't find out anything about him. Can anyone find some info?