Hand-Painted Watercolor Postcard Of Grapes (or Olives?)

At first I thought this lovely hand-painted postcard depicted a bunch of green olives still on the branch, but now the structure of the leaves makes me think they may be grapes. Either way, a really lovely little watercolor (or perhaps gouache) painting of a sumptuous little bounty! 

3 1/2" x 5 1/2", with richly saturated color on a warm cream stock. British and early 20th century I believe.