Estes Black Brant XII, Kit # 9723 Build, Part 15, Shaping The Hatch Detail

After the bottom curvature is sanded in,

Do the top curve keeping the height consistent from side to side.

Sand the front angle using 400 grit on a block.

Sand the side and back angles in.

Here's a finished hatch piece ready for filler.

I'd recommend filling the balsa grain before gluing unto the model.