#1- Simple Top:  Add a new layer and name it simple top.  Draw a rectangle selection along the top of the fireplace.  Flood fill it with your wood pattern.  Click on the Deform Tool.  Place the cursor over one of the top corners and hold down the Ctrl key.  Drag the selection outward.  Release the Ctrl key and squeeze the selection downward.  Say ok to the deformation.  Note that you will need to use the deform tool on the brick insert to pull it up more for this version of the top.

Add a new layer and call it top 1.  Use the selection tool to create a selection that is wider than the fireplace and about the same size as you see in relationship to the fireplace in the screen capture below.  Now flood fill it with your wood pattern.

You may have to become very creative with the Deform Tool for this step.  First put the cursor on one of the bottom corners and hold down the Ctrl key.  Squeeze the bottom sides in so that they meet the inside of the left and right sides of the fireplace.  Let go of the Ctrl key.  Put the cursor in the middle of the top and squeeze the selection downward.  If you notice that your top piece is not wide enough, stretch it by putting the cursor on one of the sides and pulling outward.  You may have to use the Ctrl key again to readjust the bottom part of the top where it meets the sides.  The image below is how it should look before you say yes to the deformation.

Add a new layer and call it top 2.  Once again use the selection tool to make a selection that looks similar to the image below.  Flood fill with your wood pattern.  While the selection is still selected, use the Outer Bevel with the same settings as before.  Hit the Brightness/Contrast once or twice with the same settings as before.

Before you deform this piece, trim off the bottom part of it that has the bevel.  Now click on the Deform Tool.  Hold down the Shift key and put the cursor in the left top corner.  Push inward.  Go to the right corner, hold down the Shift key and pull outward.  Let go of the Shift key and put the cursor in the middle of the top and squeeze down.  After you say yes to the Deformation, change the Opacity of this layer to 70%.

Click on the Draw Tool and use the settings as shown below.  Pick a color from your sides and add a new layer called line 1.  Draw a line from where the top and the side meet down to the bottom of where they meet.  Zoom in and trim any excess line.

Go to Image, Blur, Gaussian Blur.  Use the setting from below.  Now copy the line and paste as a new layer, line 2.  Mirror this layer and fit it on the other side.