Dave Ciliberto. I ordered my original window boxes from him when he was selling on eBay and those boxes are still doing just fine despite our harsh winters here in Michigan. If you need info on the window boxes or estimates for custom sizes just use his email address at the bottom of his home page on his website.
The method that Dave uses to assemble his boxes hides all the screw heads. The only visible screw heads are on the back where no one will see them. If you order an extra long window box it will be made in two pieces but when the installation is complete it will appear as if it is one long window box. I highly recommend Dave and I am sure you will be as pleased as I am with your window boxes.
We had three windows to install boxes on. Two of the windows required extra long boxes so those were two piece window boxes and one window had a one piece window box and that was the first box that we hung.
Hanging a window box or even a light fixture on cedar shingles can pose some problems because the shingle is thicker at the bottom than at the top. Depending on where your window box lands on the shingles will determine whether it tilts back, forward, or is plumb. That is why we didn't install the partial shingles directly underneath the window sills.
Notice the bubble on the level in the photo.
We corrected the problem by installing a piece of shingle upside down so that the thick part was at the top. We played around with some scrap pieces and found the sweet spot on the shingle for the correct thickness. We then cut the scrap pieces 1/2 inch shorter than the height of the window box so that it would not stick out from behind the box.
Notice the bubble on the level now. Look who's rocking purple nail polish. I must have gotten hit on the head with a coconut. Big Bang Theory shout out.
We pre drilled the holes for the long screws that we used to attach the box to the house. Once the box was hung we installed the hanger/bracket/supports. Again if you just attached them on top of the shingles they would not be plumb nor flush. So we marked the outline of the support using a pencil and then cut out just the top shingle using an oscillating saw.
We also had two windows with the two piece window boxes. One window required the upside down shingle trick to achieve a plumb window box and the other landed just right so that we could screw it to the house without adding the upside down shingles.
The two piece boxes are made so that the trim covers the area where the two boxes are screwed together. It looks like one long box when completed. Can you imagine trying to hang a window box that long or trying to ship one that long?
The window box is level. The camera person obviously was askew.