Tiny (Parthian?) Bronze Coins

Agreed they are the right size/weight for Parthian chalkoi.

I'm pretty sure your second coin is Artabanus II. For similar see:
http://www.coinproject.com/coin_det...?coin=231949
http://www.coinproject.com/coin_det...?coin=111580

First one appears to have a Nike reverse (your top pic). If it's Parthian, this limits the choice down nicely to Vonones I, Parthamaspates, and Vologases IV, I believe. (a couple other rulers had Nike reverses on their chalkoi as well, but with square borders or multiple legend lines...so they are out of contention) I originally thought Vonones I, but the reverses on those chalkoi have no border as yours does. Really, then, if Parthian it is likely Parthamaspates or Volo IV. I am leaning toward Vologases IV at this point but, again, if you can get a better image of the obverse (your second pic) it would help greatly.

Hmmm. Hard one...I hate to admit defeat, but without the coin in hand, and with a loop to get in tight, I'm stumped...and, even if I could inspect it closely, it may simply be too far gone in its wear. I'm also less confident now in my assumption of the reverse being Nike...it could, I suppose, be an eagle.

The new pic you provide of the obverse seems to show a long straight beard (if I'm reading it right). One possibility is, as I suggested earlier, a chalkous of Vologases IV...although the new pic is steering me away a bit from that idea. Another possibility is a mule of an Artabanos III obverse and an eagle reverse of Pacorus II (Sellwood 77.13 reverse). Artabanos II is another possibility based on the straight beard, and he did issue a chalkous with eagle reverse (Sellwood 63.23).

The challenge here is that Parthian chalkoi are very poorly documented compared to the silver issues - AND most are in terrible shape.