I don't normally advocate for the use of electrolysis, but in this case I used it.
"This coin was in rough shape when I bought it. I could tell there was nice detail, but there were also many problems. There were a few red blisters where the corrosion was especially bad. I started with electrolysis, which was not removing the blisters of corrosion. I finally completely stripped it using a dremel with a brass cup brush. I re-toned it with Dellar's. The surface is a bit rough, but the detail is very sharp."
My page about this coin
http://www.constantinethegreatcoins.com/ROMAE/There are two other coins below it which turned out nicely also. Caveat...I have not included any pictures of the many coins that turned out terribly!
