I am looking to identify my float bowl. It is satin amber glass..base measures 19cm in diameter. it is 7cm high and has a 12cm diameter frog with 19 holes. It has a raised imprint RD 813115. I have done some research on the number and think it denotes Sowerby 1936. The problem is I can't find anyone to confirm this is correct, nor can I find another with which to compare. Can anyone help please.