The denomination can be deduced from the diameter of the coin. Although sometimes it is easy to work out stylistically.  With regard to pictures, your best bet is in natural daylight and take plenty of pictures to increase your chances of getting a sharp one. Pre-Treaty is indeed 1351-1361. As for the legends, the outer legend on the reverse reads: POSVI DEVM ADIVTOREM MEVM which roughly translates to 'I have made God my helper'.