(Top left) Notice the youthful appearance of Agrippa
Various ways of "explaining away" the coin:
http://books.google.com/books?id=3RIvAAAAMAAJ&pg=PA144&lpg=PA144&dq=%22year+10%22+%22agrippa+II%22&source=web&ots=gVjW2FeJZH&sig=bYf4FE7lnc0q7mFqeRwqQQJBrf8&hl=en
On Reichardt's discovery of a "year 10" coin for Agrippa cf.
http://books.google.com/books?id=ejUGAAAAQAAJ&pg=RA1-PA115&lpg=RA1-PA115&dq=H.+C.+Reichardt+agrippa+%22year+10%22&source=web&ots=I2YVMLXYrm&sig=8O5hY1SySwCY-qPxk4gMTvwZbeA&hl=en#PRA1-PA115,M1