Response from Roger Stevens [Gravesend, Kent UK]
The 'Olympic' model name was used from 1949 thro' to c1971, so plenty of scope here !! The head badge looks a later one, but as the rivets are not original, you probably don't know if it's period or not. Mine has a transfer head badge, not a metal one. The shape of the frame looks more modern than 1950's but I'm not an authority. Best solution is to send pics. to the V-CC Claud Butler Marque Expert. GIVE HIM A FRAME NUMBER. I'm sure you'll get some sound information.
Pic. of my 1949 Allrounder [lugless, but the shape is distinctive for the period] available. E-mail me for a pic. if interested.
You could also look at 'Holdsworth Bicycles' at homepage.ntlworld.com/nkilgariff/
Roger roger.stevens@cummins.com