First you have to decide where to put your 1920x480 display in the Windows Raster. This will determine what the (x,y) coordinates have to be for items that you want to appear on this display. Then you have to size the items so they fit on that display the way you want them to look.
I have two sensor stats displays - One is 1920x480, mounted in portrait orientation. The other one is 1024x600, mounted in landscape orientation. I made an overview page that populates both of these displays at the same time. To do this, I had to decide where to put these displays in the Windows Raster. Then I made the objects in my overview page the sizes they needed to be to fit on those displays in the layout that I wanted. Then I had to figure out the (x,y) coordinate for each item based on where the displays are located in the Windows raster.
Here is where these displays are located in the Windows raster. The 1024x600 display is #2. The 1920x480 display is #4.
Here is what my overview page looks like on each display. This is a bit more complicated that what you are trying to do but its the same idea. The 2 main displays (#1 and #3) are each 1920x1080. Display #1 is the Main display in Windows. The upper left hand corner pixel of display #1 is x=1, y=1, The coordinate of the upper left-hand corner of the upper left gauge on the 1024x600 display (#2) is x=3841, y=1. The gauges on this display are 150 pixels x 150 pixels. The coordinate of the the upper left-hand corner of the top gauge on the 1920x400 display (#4) is x= 4865, y=1. This gauge and the one under it are both 450 pixels x 450 pixels, The smaller gauges underneath the 2 big gauges are 240 pixels x 240 pixels.