Graphics to split over 4 store front windows in AI

It looks like a pretty easy job to me. The first thing you need to do is physically measure the window panes and the width of the bars separating them. Window pane sizes alone will not work; the curving edges of the orange background shape will not line up. If you can't measure those details someone else will have to do the work. Sometimes clients can be trusted to do that work, but most often not.

Once you have the measurements needed, create a new Illustrator document and create the window panes and frame details numerically sized to the measurements taken on the job site. Those window graphics look like they would fit within Illustrator's max art board size. So you should be able to create the design at full size. Re-create the client's design, composing in the window panes the way the client desired. You can use the Pathfinder tools to knock out parts of the orange background where the window frame lines are hitting. You'll have to use the clipping mask function for the photo image, making at least two copies of the image to isolate in a clipping mask for each window. Cut lines for a plotter can be made just from the orange background shape. I would stick the cut lines on their own layer.