https://skydrive.live.com/redir.aspx?cid=31bcfe94dd067f8f&resid=31BCFE94DD067F8F!522&parid=31BCFE94DD067F8F!521&authkey=!ANXHaYnGD-8N6c8
The first is a 4th century roman bronze, looks like Constantius II, and another looked like a medieval coin with a thick legend around the perimeter. That's all I could tell from these.
Then I guess your fourth image is upside down. I simply can make out a legend trace. Bottom line looks like late roman, most likely Constantius II.
Looking at the obverse I believe that the head is bare rather than laureate so that narrows things down a bit. Looking at the reverse we can see SIS at the bottom indicating that this was minted in Siscia. Also on the reverse I believe that we can see a kneeling Victory, facing left on the lower right area of the coin with what looks like a galley. Combining all this leads me to believe that the coin is an AE3 of Constantius Gallus of the FEL TEMP-REPARATIO, Emperor on galley type, minted in Siscia. Regards, Martin
