stoneware vase/lamp base, Leach??

This nice unusual shaped vase/ lamp base in green and brown colour pattern is stoneware , I think from st ives cornwall as the mark is an S with an I through the middle its in excellent condition and I would say not too old , poss 70s/80s I thought it was a vase that had been drilled but looking at the hole in the side I think it was made as a lamp base as some of the brown glaze has gone inside the hole , any comments welcome