Kelvin produced seemed to have produced nautical creatures in the 1960's rather than in the 40's/50's.  I don't collect many Kelvin items so have not investigated into their origins.  The only things I have from Kelvin are a whale spoon rest and cream/sugar.  They made a pretty mermaid too.  There are a pair of mermaids facing each other that look similar to the Kelvin mermaid.  But they were made in Japan and are shorter and fatter.  I've also seen whale salt pepper shakers.