I just found this again and was wondering about it.
When I got it two years ago, the dealer (Jason Failla of Failla Numismatics) didn't know what it was. It looked promising, so I got it for a couple of dollars.
O: Helmeted bust?
R: Bull charging left. From what I can read of the legends, I see 'RMANV' and 'VTI...', not sure what the other letters/symbols in the lower word are. I don't know a lot about ancients, so my first thought was that it was perhaps Roman Republican based on the RMANV and Latin letters, but Failla didn't think so. 2.9 g, 17 mm.

Thanks!