It's wonderful example of an early copper, well done!
as for cleaning, I would only suggest a hydrogen peroxide bath for a couple of minutes, then let it dry on its own
this will eliminate most of the corrosion without disturbing the patina too much , don't rinse it with water when done either, simply pat it dry if you must
I normally don't suggest cleaning at all, but your coin looks like a mild cleaning will bring up the already strong details and improve its eye appeal greatly
good luck with it and continued success at your site