Had to rescue our 1968 S11a 88" earlier this week as it had died at the roadside.
We towed it back to our workshop with our ex Army Defender, up one of the steepest hills in the area.
It was soon found to be an electrical problem caused by the rev counter (fitted many years ago by a previous owner). This had earthed out the low tension and stopped the engine.
Removing this and many other redundant wires restored it back into use again.