Length of Cork Handles on “Octofloat de Luxe”

[Mike Crompton]

Hi, Everyone.
I have a number of 11 ft “Octofloat de Luxe”, three piece split cane rods. The length of the Cork handles vary from 17 inch and 19 inch. I believe that there is also one of 24 inch. This is advertised on page 10 of the Sealey fishing catalogue 1969. Has anyone knowledge about the dates of manufacture of the ones with shorter handles? Does the shorter handle indicate an earlier date of manufacture? Is there a definitive list of dates showing the changes when the handles were changed?
I know I ought to get out more often but this question has bugged me for some reason.
Thanks.
Mike

[Andyman]

Not sure about handle length but logo gives a rough idea of age.
I believe the two fish design is '65 or later. Sure that someone else can be more specific.
My de luxe is pre '64 ish, will measure handle and get back.