Thats it, and is good you copyed the values for all resolutions, this will help to understand what im going to explain
The point is... sony and us should work always in 1080p resolution because this is the highest quality, and the positions and sizes for the other smaller resolutions are achieved by scaling down the images
As you can see in the xml of custom_render_plugin.rco there is a <Plane> object named "ps3logo", and it have 1 attribute where it loads the tex_ps3logo.gim
planeImage="image:tex_ps3logo"
That image is the original logo used in the gameboot... and is the image we are customizing
The size of the original GIM image matches with the size values in the layout .txt files. For 1080p that image is 1200x128
And that values are loaded from the layout .txt by using this attributes:
sizeOverrideX="0x9c020100" <--- this is the one who loads the value 1200 for 1080p
sizeOverrideY="0x9d020100" <--- this is the one who loads the value 128 for 1080p
We have replaced the image by a different one with size 300x300 so... we need to change that values, and there are several different ways to do it