The first part of the trick is ok, but you display the four indifferent cards and only one queen after the supposed separation has taken place. I feel that many laymen will notice this kind of minor discrepancy.
In the second part, what you are doing is visible.
The kicker is interesting, but I remembered that you had never shown all of the backs before in the trick. You did occasionally show the back of one or two cards. I'm not sure if laymen will catch this, but you need to think about this. Maybe you could use a Hamman count at the beginning to show all the backs to be the same color?
Also, check out Roy Walton's Oil and Queens. It is not the same as yours, but it is a nice trick all the same and might give you ideas for improving your version.