If you double crush - try throwing in some rice hulls and running off slowly to start during the Vorlauf - when its clear, let 'er rip. efficiency questions are almost always volume and temperature related, but I also found that going up to 1.75 quarts per pound or even a little higher increased the mash efficiency. YMMV, of course. The fellows above really know their shtick, so you should have most of your problem solved by following their lead.
Good luck and don't give up tweaking!