About the twins (and the CB500-4): many of them came with 'soft' or 'porous' cam lobes. These develop into the kind of pitting you see on those lobes now.
Interestingly, Honda wouldn't supply a new cam if these were found in an in-warranty bike. Reason: the pits don't have raised areas on them to attack the rockers' feet, and instead act as an extra oil-wicking site into that sliding bearing. It was (as still is) rare to see grooves in the rocker feet that correspond to such grooves: look closely at yours to see if this is the case.
This all said, 50 years later: many of those pits have turned into water-holding sites when the bikes were parked long-term with old, used oil in them. Then the DO rust, and raise a sharp burr that can cut into the rocker's foot.
So...look closely and see if your rocker feet have corresponding grooves that align with scratches around the raised lobes of the cam(s). If so, the damage has begun. If not, the engine was likely parked with the old oil and left, and now you are restoring operation. You can now use superior oils in time to save the cam and rockers!
I've rebuilt many 350/360/450 engines with pits like those in their cams, and they were fine. Even some 500-4 engines have been done that way by me, with no ill effects years later.
If you decide to get it fixed: I'm 100% onboard with Megacycle's work. I won't use any other non-Honda cams in the SOHC4 engines, myself...
