I still not fully understand you: Do you have the Addon Manager menu under the "Addons" menu bar, but you are missing ONLY the Couatl and GSX menus ? Is this your current situation ? Just say Yes or No.
I have all the Addons menu showing in the dropdowns, but can't get the popup menus to show (crtl+F12 doesn't work)
I don't understand how to install just the "content" of P3Dv3.3 since the LM site doesn't let me just download "content" only.