There are not many Parthian chalkoi with seated archers - a motif that is, of course, more commonly associated with drachms.
Yeah, when I posted that coin elsewhere (a few hours ago), I was immediately told it's a drachm. When I mentioned the size I was told it's an obol and given a link to a type that clearly didn't match by motif.
Take your time, of course! I didn't intend to intrude on you; I was just wondering if "likely" meant something to the effect of "there are three types it could be but two of them are very rare".
Either way, probably worth the 1000 rubles (~$14) I paid for it... one of my most expensive ancients, but I really wanted a Parthian!