Hi,
The "Poisson Volant" is Inwald, pattern number 9830, the frog should be 12865, but is not. The bowl does not appear to match (IMHO). The centrepiece was supplied in the 1950s with an "Inwa" pattern bowl 12868. Plinth 11231 matches Inwald catalogue circa 1958. (Info courtesy of Sklo Union: Art Before Industry, by Marcus Newhall)