I have just joined this forum and have found this thread very interesting as I have a jazzette of my own which as rare as they are in the US are almost totally unheard of here in Britain.
Welcome fellow Jazzette owner. Beautiful kit.
Your opening statement begs the question: did you buy it locally in the UK, or import it yourself? I imported mine myself (used) from the USA. Probably the only one in NZ. We're more a place to find vintage Premier and other UK brands, although a number of American made drums certainly came in.
I don't think it is too difficult to imagine a man walking into a drum store, seeing a jazzette for sale, loving it but telling the shop owner he doesn't like metal snare drums and the owner offering him a jazz festival snare instead, I imagine it happened all the time.
I agree with your assessment of excessive "catalog correctness" potentially getting in the way of sonic and visual enjoyment. My 1963 Jazz Festival doesn't fit your scenario because I bought it separately (before I got the rest of the kit which dates to 1969/70) and paired it up by my choice rather than reading a catalog to see what I "should" have. But I'm always up front about that.
I think the issue some vocal people have is that some sellers might attempt to pass off an assemblage of drums as a kit which left the factory together. It's a worry because once that kit is sold with a false story the story has a way of being passed on as if it were true by those who don't spend as much time as we do pouring over old catalogs.