Just had a close look - by the way mine looks pretty centred to the naked eye - and looking at the filter holder from the front (looking into the lens) the top of the right-hand post sits slightly proud of the holder, and the holder and is seated fully down against the stop ring on the post. The left-hand post top is flush, but there is a gap to the stop ring, it's not fully down. The whole unit is solid as a rock though. This implies there's perhaps a 1/4 turn difference in the seating of my 2 posts, but I have centred filtered.
It looks like my posts have got perhaps half a turn more into the screw hole than yours, maybe?
Take a quick snap or two - any vignetting? If not, I wouldn't sweat it if everything is tight and there's no play.
