msfossey,
When you press the keys, Ctrl + Alt + Shift + G, to activate the built-in MB-GSL-Editor no bells or whistles go off to let you know it's working.
The MB layout window doesn't act any different or look any different after activating the built-in MB-GSL-Editor than it did before.
Have you tried just creating a layout, saving the layout to the GSL, Ctrl + Alt + S, exiting MB-GSL-Editor, Ctrl + Alt + Shift + G, and then opening FF or whatever to see if the scenery objects are installed?
MR
BTW, if you are using Lindsay Watts GSL Editor tutorial then you should be aware that there is one small error. In it he mistakenly gives the key stroke combo for saving the layout file to CFS2/Layouts as Ctrl+E. It should read Ctrl+W.
Do not confuse this saving of the layout to the CFS2/Layouts folder with saving/installing the layout to the GSL.
One other thing: If you decide to use Martin Wright's GSL Editing tools remember that Martins tools will overwrite any objects that are already present in a particular GOB. The built-in MB-GSL-Editor, on the other hand, will add objects to those already present.