I bet that's it VK, there isn't enough room on the flan or another janus face like I suggested before....I don't think.
I guess the thing now is determining whats above the prow. I've looked at it many times and at different angles but haven't been able to spot a star or any other letter/symbol.
Because of the several reductions of weight, you can find various different weights for various denominations. Here are my 40.0g as and my 14.17g uncia (one dot=1/12 as). Both are struck coins but not too long after the cast aes grave.
There's beardless versions of this type? Seems like this just got more complicated, because I can't tell in hand if it has a beard or not
As Doug points out, Andrew McCabe is one of the leading authorities on Republic coins. Here's his website, which offers copious information for attribution... http://andrewmccabe.ancients.info/ My one and only Republic bronze, a semis with Saturn on the obverse...