yep they're slightly different, the first thing I noticed was the locks of hair at the neck, they are differently arranged, I've never studied ancients before, even after nearly forty years of collecting! but I'm quite facsinated by this coin I have, its worn, looks like it been 'dug', but is centrally struck, and still collectible I suppose. I would like to say thanks to everyone for spending time to answer my questions, much appreciated, Constantius II ruled for about 20yrs, so in that time many a coin was minted! and there would have been more than one moneyer producing coins, so there must be different die types,