I have a print titled "LOCH ORR CASTLE" published June 11, 1790 by L. (J?) Koopen. It shows a narrow loch with the castle out in the water with a fisherman standing on the near bank. The print indicates the castle was in ill repair I cannot find a Loch Orr on any map of Scotland I have seen though it could have been somewhere else. I think it is probable I could scan the picture and email it if anyone is interested.