A quite objective question, Arran.
I do not own such a tool, but my neighbour does. Just made the test.
No fluorescence under ultraviolet light, neither paper tag nor cap cloth and seams.
I see my reply from the weekend didn't 'stick'... okay well...
Wow!! Absolutely wonderful! Even if that isn't the same Mutze in the photo 1) you're very honorable for pointing that out and 2) at least you found the same soldier out of the millions who served! That's quite an accomplishment!