I prefer my tanks clear also. I remember someone making their frosted tanks clear by using a torch or a buffing wheel. I have to find that.The SJMY version doesn't use an oring there either. I prefer the clear of the SXK, but like the SJMY for the draw, and the threading is a little better.
Since even the SXK doesn't require much tightening, I'd think it could probably do without the oring as well.