I finally got this to be functional and it's made two 5 gallon batches so far. Still has an annoying leak in the HLT, but the water is staying off the 4500 watt element, so it heats OK. That black box on top of the HLT hold a stir motor to keep the water moving around the HEX coil inside. The Boil Kettle is 60 quart capacity, so it really wants to do 10 gallon batches. I'm pretty sure that the Rubbermaid 10 gallon Mash Tun will hold 20 pounds (at least) of grain, so my next batch will be an attempt at a 10 gallon "Noble Pils" clone. It's surprising that it took 3 months to knock out a "Ghetto Special" stand like this - maybe caused by doing everything "on the cheap".
Right now it lives inside that building, but the next phase will include enclosing the porch and then it'll stay outside. I also want to build big drawers at the ends of the stand to hold hoses, etc. By the way, I was worried about water vapor and steam from the BK so I sealed the control box really well and cool it by drawing air up the two tubes from below the top deck. That fan in the back is 110 volt and moves a lot of air past the SSR's inside. Thought about adding an "air screen" below the control box, but right now it looks unnecessary.