Well this is all very interesting but not really helping with my original question 😀

So no-one has any historical information on the development/use of the light then? :confused:

I think your original question was answered sir !
Basically there is no such thing as a ‘Harley Light’
The Harley company made many various a/c lights for many different a/c types.
The ‘Harley Light’ is just a normal lamp fitted in the nose of some naval a/c to make tracking/visibility easier for certain training roles.
I am sure if you google enough you might find out some details of the company but as you are prob aware,you will have to wade through oodles of Harley Davidson stuff first.
It is quite normal practice in aviation to use a trade name for a component… ie… a fuel tank pressure control valve on a Harrier may just be known as a ‘Hymatic’ valve,it is(was) made by the Hymatic company but they make many different components – not just that one.

cheers baz