David, Brian, Mark etc.,
I am not sure how helpful this may be - it may just add to the confusion.
The Bicyclesport, Toronto, catalogue for Spring 1980 was still listing Mod.61 alongside Super Mod.68, Corsa Mod.77, and 'Competizione' Mod. CX.
Their entry for the Mod.61 reads "a very well designed centre pull brake. Supplied with the very popular Universal lever with rubber hood."
The Super Mod.68 is described as "the old favourite"!
It seems that the same lever was being sold with both the Mod.61 and Mod.68 at that time.
Paul Williams,
Ottawa, Ontario, Canada