Hi William,
I have looked at your file and notice the following issues:
1) Looks like originally your file was created from one of the GWD Template which has a 160x600 dimension:

2) And I saw the following publish metadata info at the end of the file:

This is probably why you always see the ad published in 160x600 size because the metadata info is set in the file.
(Usually you will see this metadata info in the published file or the html file from the gwd_preview folder. I think it is possible that the designer sent you the file from the gwd_preview folder instead of the original source file. Can you ask for the original source file from the designer? I recommend to use the original source file for publishing and editing - such as changing the ad size - see the next point.)
3) I have tried removing that line of code from your file and republished it. But then it will fail at uploading to AdWords because it has the wrong size (325x50) that is not supported by AdWords:

4) Looking at your screenshots again, I wonder if you were trying to create a file that can be published into different ad size? I think using a responsive layout file would be better for this kind of workflow, please visit the following links to learn more about using responsive layout in GWD: