That is exactly what I did Paul. The top row of smaller panes first all the way along the front. That took 15-20 minutes or so, then back to the start point and the larger lower row all the way along. Then the same down on the ground floor.
It was a good hot day today and that stone-work is bone dry so what went on it didnt hang around too long.
Problem is there is ALREADY stain marks on the lower row of glass due to rain-water running down over the stone-work. Ive got an extra day out of them to go back and apply some cleaner to these parts. Not sure but hoping limescale remover will do it. What say you?
Matt