I’m located in McAllen TX, a border town!
Re the fuses : are you referring to the glass cylinders in the screw cap enclosures on the top of the back plates? I switched them with no effect. Are they even fuses : they are glass cylinders with a metal cap on each end but I would expect to see a fuse wire down the middle but the cylinders are both empty; do the functioning fuses lie inside the back plates?
I think your idea of switching the back plates is very good, I hope to try it out on the next day or two as soon as I’m able to