The link was removed because it was to some legally dubious free pdf.*
Anyway, the 84-86 CB750 is what the US knew as the CB700, the angular Nighthawk S. It should be very easy to distinguish these bikes in any photo.
Model years and calendar years are not the same thing. Having bikes/manuals of a model year made a month or more before the same calendar year is normal and expected.
*From Forum Guidelines
http://nighthawk-forums.com/index.php/topic,6.0.html 8. Discussion of the unauthorized reproduction, distribution, copying, or theft of copyrighted materials is forbidden.