The locknuts are on the cables, I got these terms from the haynes manual heh heh!
The cables route through a mounting bracket on the carb before going to the throttle cam, the cable has two nuts either side of this bracket - the rearward one is the captive nut and the front one is the locknut.
Just to check - the front cable on the throttle switchgear - the opening cable - this is the one that goes around the top of the throttle cam, routing around to the rear of it?
Thanks again everyone