I find fasteners and brackets in all manner of condition; most are salvageable and some are just too far gone, but many are specific, non-generic fasteners so you don't always have the luxury (or budget) to replace with new. The first photo shows how the 6mm clutch/alternator cover bolts looked — corroded, dirty with a generally "dry" metal appearance. After cleaning, I gently buff the fasteners with a soft rotary brass or steel brush on a medium speed and see how well that works. I also wire brush the threads. Resist the urge to use a bench grinder-style wire brush, you will remove any paint or plating and end up with rusted bolts. I then wipe them with a metal protectant, like Corrosion X or ACF-50 which will help bring back the dark color. There's about 25 of these bolts for just the engine and valve covers, so you'll need a bit of time. Alternatively, these bolts are still available from Honda; about $40 would cover all the clutch and alternator bolts. Small brackets also benefit from this effort — the fuel pump holder is pictured with some finished bolts.
Yes, it a labor-intensive chore but, yes, it takes your project to the next level.