This is one of the last pics I took of my shelf layout, before I completely dismantled everything above the plywood. I have now restarted, placing a one-inch thick piece of blue styrofoam over the plywood. As noted elsewhere, I was forced to use too high of grades to get to the addition on top of the credenza (left part of the pic). We've also redesigned the home office so my wife can have her own craft area, which meant getting rid of the credenza. I now have a track plan and budget for my 7' x 10' donut-type layout for the garage. Construction to begin April 1 (when I get a new "train budget", and hopefully it warms up significantly - it's -20C today).