I came across this catalogue, which has a couple of pages for glass: one for Scottish glass and another for Amalric Walter pendants. The museum recently purchased the pendant numbered 412. We thought it might be dated from the 1920s but the catalogue suggests a slightly later date. Just look at those prices! Our pendant is priced at 5 shillings and 6 pence. Even for 1930 it wasn't too bad.
There is a better picture of the pendant on the museum home page:
http://www.isleofwightglassmuseum.org.uk/Anton