I have a 2010 Optima, it is drilled for both iron sights and the dura-sight scope mount.
Last year I bought a CVA Wolf, it has iron sights and is also drilled for the scope mount. It had a little plastic bag with the plug screws for both the scope mount holes and also the iron sight holes. They are not the same size, the iron sight hole plugs are tiny.
I have been intending to call CVA Customer Service to get some of the iron sight hole plugs for the Optima. I called them awhile back for some firing pin springs, they were nice enough to send two for free. Give them a call, their number is: 770-449-4687.