The glass (i.e.the actual items with the impressed heron design) was made by Josef Inwald and was shown in their 1934 catalog. The items shows in the eBay auction comprise part of the full set.
Looks like a decorator (Leroc?) did the paintwork and possibly added their own etched mark. It's possible that the RD was for the Inwald design. I don't think Inwald would have added an etched mark, it's not their style of doing things. They did sometimes use a pressed RD.