I have added another post to my blog. I step through the process of copying an interface (GUI) definition from one datasource to another.
Please take a look and let me know if you have any questions, comments, etc. Hopefully, you find it useful.
To the group....
Found something out today while running this, You do not want to have PW Admin open and have the destination interface selected, it will not update.
If you simply select focus on any other interface it will run. I suggest not having PW Admin open at all.
HTHs other trying this out.