Contrary to popular belief, I don't subject ALL of my coins to extreme chemicals. This one had a bit of mineral encrustation. I soaked it in distilled water, working with a dental pick every day. After I got tired of waiting i tossed it into some hydroxide for just 15 minutes or so, so as not to completely strip the patina. After some ren wax, it looks a bit nicer and I can actually see some legend on the reverse and made the "MAX" on the obv a bit cleaner. Now with the MAX and the III revealed, I can properly attribute this as RIC 431!
