Matt, you have the Cream of the Norton Commando crop. Long distance smooth riding sports bike surpriser. About the most unique outside feature of real Combat is the big breahter hose coming off the bottom rear of crankcase. Of course upper engine could of been changed but likely not.
Only real down fall of factory issue Combats was so strong they'd over rev em on the flat roller DS bearing till crank or bearing cracked. The road mates they were playing and beating in that era were the 3 cylinder 2 smokes 750's duh.
Both my Combats had original DS flat roller and TS ball bearing in about pristine condition, which mean they were not lugged much nor run over 7000 much.
You do not have to change them as long as away of them in there. Valve float
can hit in factory head just when ya don't want it too like passing a semi truck
and bad noises as power losss happens before you zing ahead of it in 2nd or 3rd.
Trixie my New Orleans rescue before Katrina hit, has blown up bad twice, once by the piston let go then by a weak re-used rod bolt, all in just plain touring mode but still using the old bearings fine as long as not topping out to redline all the time. Little need too for sane thrills on a real Combat even with 6 gallon is tank and cargo loaded. Much rear cargo tends to wheelie them in surprise btw.
++++++++++++++++++++++++++++++++++++++++++++++++++++++
Most dangerous feature to be aware of before riding I found out the scary way is if front brake has a leak undetected, works a charm perfectly right up to the next pull when its completely gone no warning at all. LIkely all rusted inside it but still functional - just slow leak that get blown away to fool ya. Check fluid in master cylinder each gas stop for 1000 miles to know how much to trust it on an under 13 sec 1/4 mile sprinter. *********************************
Another reason to open up besides dial measuring the cam profile to verify its a 2S cam - is my 2nd pure Combat had the old oil hole slotted pistons with an Al gasket, but runing just fine w/o doing anything to engine - until the weak pistons rubbing on extruded Al gasket came apart.
READ through the Technique Notes - Photo Posting at top of forum list for scope of what you should be aware of as baseline Commando kit.
