I finally got the rest of the yarn I needed to complete the ruffle on the Sursa shawl from Cornelia Tuttle Hamilton's book Noro 2.
In fact I used just over 180gms instead of the 100gms stated in the pattern. Maybe I shouldn't have used the ruffle yarn double like the rest of the shawl but the instructions are not ambiguous - "Using Cash Iroha held double pick up 1 st for every row...." etc.
And the dimensions of my shawl match hers so I don't know why I needed more.
However I'm really pleased with the finished shawl and the colours are lovely.