All the replies are much appreciated. Thank you for taking time to contribute.
Yes, the star on the seat tube is the cut out taken from the head badge.
The bike rides really well - smiles on every outing & the relative lack of weight in the wheels compliment the performance of the frame.
One further photo here and a link to this extensive London Cycle Campaign article, with further information on the frame builder & the history of Roberts Cycles:
https://lcc.org.uk/articles/roberts-cycles