Sorry for the late response Peter. I knocked a cup of Coffee over my laptop a couple of weeks ago. & yes, it is buggered! Writing this on my newly delivered an hour ago. Laptop, via house & contents insurance!
Yes, you are quite correct with your comments above. When I left Warminster, there were TWO of these borsighting MkI aids. Sitting on the dexian shelving, in the Armourers Shop. They never left those shelves in the 2 years I was on attachment there!.........I have one in the Collection myself. Acquired approx. a year ago.