The first 2 solutions were out of it because it's not just firefox, it's right across the board.
As per the 3rd suggestion, I changed the GtkScrollbar::slider-width setting in /usr/share/themes/Adwaita/gtk-2.0/gtkrc to no effect and the only file in /usr/share/themes/Adwaita/gtk-3.0/ is gtk.css which has the one line: /* Adwaita is the default theme of GTK+ 3, this file is not used */
I've also installed tweak-tool but nothing there.
Edit: Tried to change the overall theme, I guess "Appearance' in gnome-tweak is the only place I can find to do it. 'Shell Theme' is disabled and 'GTK+' has only choice of Adwaita or HighContrast even though /use/share/themes has Anaconda and Raleigh listed.
Anyway, thanks for the help, f it, I quit.
Last edited by hognoodle; 04-24-2015 at 02:30 AM.