Maybe even an MS66, on a good day? My 1881-S is an MS65, and appears to have a tiny bit more chatter in the left obverse field than yours does (though it's hard to say for sure with the lighting in your photos). So by way of comparison, I'll change my guess to MS66, on yours. Nice coin, regardless. .
MS 66. Tough date to get that grade, due to survival of high quality coins, but I think this one makes 66.
I would have to get out my Morgans to check the condition of my 1881 S, but I doubt mine is as nice as yours. Thanks for sharing it to us.