Estes Klingon Battle Cruiser, #1274, Step 18, Engineering Hull Prep

The engineering hull top is a curved piece of cardstock.

Gluing flaps are folded underneath the exposed top. I burnished mine with a Sharpie pen barrel.

A close up shows the broken edges at the card stock fold.

A rub of medium CA glue was applied with a Q-tip. This hardens the fuzzy edge so you can sand it square with a sanding block.

The hold down tics are smoothed down with a sanding block.

I did some dry fits and found the cardstock front  wouldn't follow the curvature of the vacu-formed hanger deck piece.

A curve was pressed in the same way I curve a card stock shroud. 

Set the card stock over the soft heel of your hand. Press and roll the Sharpie barrel over the card stock. You should get a curved top. 

A dry fit - 

much better.