Coins Of Olbia: Date?

1) This looks close, corn over a dolphin with Olbia (in different language) below. Puts it around 325 - 320 BC.

(Apparently this forum doesn't allow special characters... click the link to see the characters on the actual coin)




http://www.vcoins.com/en/stores/cal...Default.aspx

2) I believe this is a depiction of a crowned Demeter on the obverse with an archer on the reverse. This would place the coin somewhere between 200 - 150BC.

Source

As for denominations, I'm really not sure. Your first coin seems to be about the same as the other examples I found, but the second coin is significantly heavier. Though I'm not sure if that indicates any kind of denominational differences or simply inaccuracies in weight measurement during that time / in that locale.