The 1962 Holdsworth catalogue has the following text inserted into its freewheel listings:
"STOP PRESS: REGINA SIX SPEED By fitting a special sprocket (No. 8) between the standard next to top five cog (No. 4) and a 13T cog (No. 7), six sprockets may be mounted on the standard body. This new cog is available initially in 14T or 15T only. Freewheel complete 24/6"
Gene Portuesi's Cyclo-Pedia, Sixth edition, 1964, lists six speed French Cyclo freewheels.
Peter Brueggeman La Jolla California United States of American pbrueggeman(AT)ucsd.edu