Doesn’t the quickstart package instal Joomla, Gantry and all the particles? I already have Joomla/Gantry installed along with dozens of Articles already.
I reinstalled the J: Content Grid and JLUikit particles/atoms and all the CSS, JS and SCSS files, replacing what was there. I recompiled the CSS and deleted & reloaded the JLUIkit atom. The I set up the menus as you suggested. Your instructions did not mention the layout where the Content grid article is (Helium-Blog Style) so I assigned the TMR-Menu menu item to it. That seems to have done the trick except that I get an x next to the TMR News menu item where the hidden menu would be if it wasn’t hidden. I guess I can live with that.