Hey Ludwig, that was hilarious!
One of the problems that plagues restorers of all things mechanical is information. Of course, there are people who make stuff up to suit them & it gets repeated, but also the factory information (esp. at Norton) was sketchy at best, I have seen one owner bikes bought from dealerships in colors that werent available that year, & with features that weren't available on that bike. These are bikes that I know the owners personally, not some made up story. Then if you consider the so called "factory documentation", very few people in the world have access to some of this info. I know of one guy who sat at the science museum in the UK for hours & hours transcribing info from films to pen & paper. Some employees took paperwork home with them, who will ever see that info? Some info (and parts for that matter) were just thrown in the trash bin (per Paul Dunstall). So, how is information proven in a case like this??? Paperwork helps, but again, proving anything with factory info, or using the often wrong parts books from Norton, Lucas, Smiths, Girling, etc. Whose to say. I personally would trust provenance over a factory document every day of the week, or a shop employee eye witness over a secretary in the front office .
Off topic on this particular bike, but on the subject of factory records, here is an excerpt from a letter I got from a factory employee about the supposed green candy paint on a G15CS exported to Canada, the subject of "factory records" was challanged & he told me:
" The last batch of 350 singles with Matchless badges left the factory for Rodesia in 1966 with 1/4 inch gutter bolts fixing on the mudguards [ fenders to you lot!]
Ran out of 1/4 BSF hexheads so my mate was sent to local ironmongeers to see " what he could get"!!! Bet that's not recorded in any records!!!"
Just one of several pages of errors I have listed on Norton/AMC errors.