The rim looks squared off to me personally. Not getting my hopes up but would like to get others opinions.
Now i am no expert on this but I think even if it was a proof at one point, it wouldn't matter anyway. So then in turn would just make it a circulated coin.. But yes you are right i can see that the rim is squared too, that could just be from wear tho.
If a coin in this grade could be definitively identified as PR, it very much would matter; the wear would not make it just another "circulated coin" on par with countless business struck examples.