Clear pressed glass tazza or cake stand with what appears to be raised RD 735621 to base.
Can't find it in http://www.great-glass.co.uk/glass%20notes/regnos08.htm
RD number should have been registered sometime in February 1928. Is the registrant in the Blue Book, please?
It would appear that the Blue Book is now out of print . Does anyone have a spare copy for sale, please?