All of my marine chronometer boxes have the winding key in the back right corner. I have just seen one with the key in the back left corner. Any ideas why this was done?

Just manufacturer's variations, I think, and maybe changing customs. The most common arrangement is gimbal lock front right, key rear right, and box sliding lid limit bar left rear, but I have seen a number of boxes with the key in the left rear-usually early to mid 19th century.

There are plenty of other variations also. Some old boxes use butt hinges rather than limit slides, the key "shelf" can have different shapes, and the gimbal lock may be in the rear.

Norman

Thanks Norman.