Another interesting exhibit in the Byzantine Museum is its large collection of gold coins depicting the various Byzantine Emperors. (This one, I believe, is the Emperor Constantine VIII, who became emperor in 1025.)
Another great museum in Athens is the Benaki Museum. Its collection spans from ancient times all the way up to the 19th-century Greek War of Independence and beyond. Among other things, it "fills in" the centuries after the fall of Byzantium. Unfortunately, though, no photos are allowed in the Benaki Museum, so you'll just have to take my word for it!