Here is the link for all the previous AMD GPU drivers. During the install you can choose to NOT install the optional components and install only the required drivers. You need to choose the "Custom" option during the install process and then uncheck everything except the drivers. You can also try this with the Omega package but I think maybe the 14.4 CCC package would be best for your hardware. Perhaps even older.
http

/support.amd.com/en-us/download/desktop/previous?os=Windows%207%20-%2064