it's possible you are thinking of the 'Angular' RSW vase - which is more or less the colour of your piece, but has both shoulders and lower parts made at the same angle. I don't have one, so not sure if there should be a ground pontil depression or not. Although this web site appears to have ceased progress some time back, you will at least be able to see the vase of which I speak.
ronaldstennettwillson.com I hope this is the correct address.