This could probably be confirmed in short order on the Norton board by others more knowledgeable with the marquee.
Superman using his x-ray vision to spot a Combat at 1000 paces ?
This Combat bizzo has been discussed, ad infinitum, ever since circa 1972.
The factory wasn't very forthcoming with info, ever, keeping much under wraps.
And most of the folks involved have moved on or not said.
A lot of snippets of info have since come to light though, in dribs and drabs.
Only solid way to see what it is is to strip it down and have a good look inside.
A Combat has a 2S cam. No 2S cam, not a Combat.
And the head skimmed 40 thou
and the 32 mm Concentrics
And the C stamped on the head (can be hard to see/find).
And it could have been Combatted (or unCombatted) any time in the past 50 years....
And now with a single Mik carb, its lost that Combat edge anyway - if it ever had it.
(is that daylight I can see through the manifold ?)(or a bright clamp ...)