First off I have never given the battery box any thought, it just never landed in the gray mater when I was doing that thinking stuff. I have used a lead box up front. When I was building the Boeing I measured where the designer had the CG marked using the 25% rule, it was way off. I mentioned this to my mentor and he said that Mr. Tanzer had built a bunch of these planes and would know wher the CG was so go to the plans. Not that the inker could have messed up or anything? Anyway, the plane came in right at the advertised weight of 12 pounds. Maiden day I still mentioned the CG to my mentor, he was doing the maiden. As the plane lifted off I heard my mentor swearing at a plane for the first time and noticed how the wings were rocking and the tail was way down. He got it landed then in the pits we CGed it at my marks with wrenches and tools sitting on the nose. When it balanced out he removed the wrenches and handed them to me, said there, you ned that much weight to set the CG. The wrenches weighed in at almost 3 pounds. The cowl I made is really thick glass and it mounts like no other so in this case the lead in the cowl worked out without cracking the glass or breaking the mount on a hard landing. If it was a store bought unit it would have been dead years ago.
Just for grins I may set the plane back up for flight again this summer and mount both Sub Cs like you showed. That should lighten it up a lot!! Getting them up front farther should also get the CG where I want it without all that lead. Maybe the plane wouldn't be such a slug if I could remove three extra pounds? Do you think???