[rsk289]

Correct as ever, Dan - my eye for detail must have been temporarily clouded by excitement!
The shorter lever is the same as two others I have which are sold as pre-'73 Mustang V8 levers. In my opinion it could be dangerous to use these as I think it could be possible for the release bearing to hang up on the shorter fork fingers. At best it could disengage from the fork and a teardown would be needed to fix it.
Interesting your point regarding the original 'long finger' clutch cover design - it could well be that the release bearing sits in a different position.
Thanks again for the information - I have installed the longer fork and everything seems to work very smoothly. Going by your photo it will also look as it should apart from the narrower neck, which will be really hard to spot in situ.