Cam bearing a lifter question..
Test fit with used cam, angle reliefs cut in and dressed. Good coat of engine assembly lube on bearings and cam journals.
Put a bolt in the end of the cam for something to grab onto to help with balance and centering the cam as you install it.
Slowly wind in the cam to remove any high spots until it turns free, keep it well lubed when doing this. Stop and clean it if the lube starts turning gray, then relube and go again.
You can use some small pieces of high density foam to plug the oil galley holes to keep debree out while fitting the cam, then pick them out when done.
I say no to any sand paper as the grit will imbed into those soft bearing layers.
The fine steel wool sounds like a better alternative if you need to go that route.