The battery holder modification is simple. For the late A10 battery trays that have stamped out half-round ears at the bottom, simply grind off the ears. Use 1/16" thick sheet metal and cut two (2) pieces 1" X 1.5". Weld these in place of the original ears with the 1.5" side in the vertical. It holds the battery from moving in the lateral direction. The new replacement batteries for the original Lucas MLZ9E battery are not identical in size (thinner in the fore-aft direction). To solve that, Walt used sheet rubber in the front to "shim" it from moving and used another piece under the wire clip in the rear. Seems to keep the battery captive.