Shalom
While you are building a paper model, the curvature of the gun turret is such that you are not going to get it right. And the petal design will make it worse.
May I offer two alternatives :
1- sand the paper turret smooth and then add putty where needed and sand smooth again. Then repaint it the grey color to match as best you can.
or
2- make a vacuformed turret like a canopy.
I used the vacuform method for a large radar dome and it came out good.
here are the steps :
And yes, I do remember when these boats entered service. They made a big deal of the Gabriel missiles as well. These were smaller and fast boats after the destroyer ship Eilat was sunk.
Isaac