Hi, I am looking for help to identify 2 old cast "cash" coins I have. They are about 53mm diameter and from the style I think they are probably Vietnamese. I can't find them in Krause (I have from 1600) and am a little stumped. They have dragon designs, similar to some of the Vietnamese silver cast coins of the 19th century, but these are copper/bronze. Any help greatly accepted! Thanks, Mike H