Wow, what a result, Anne! Thank you for your efforts (especially for the links).
I had looked at Pamela's candlesticks (but obviously not carefully enough - probably concentrating my search on the 'usual suspects' rather than looking properly - salutory lesson again).
I thought the design may possibly have been registered to an agent or importer (perhaps Jules Lang & Son, or someone like Hoskins and Rose for Libochovice) and that the Blue Book may have given a registrant but not necessarily the manufacturer.
Now we have the unusual reverse situation of a manufacturer but not the registrant. Not many German pieces with RD numbers.
These are the first Streit pieces I have come across. The candlesticks would seem to be standalone pieces rather than linked to any trinket sets.
As the candlesticks are of German manufacture, would it be helpful if I put a linked topic in the 'German Glass' section of GMB?
I will let the eBay lister know of the ID, and seek his permission to add the images to this topic in due course. I will also seek permission to add the images to the RD number photo database for further reference.