BSA used a similar slogan to this Norton advert,in numbers of bikes made Norton are a close second to BSA.BSA and Royal Enfield both released a book/booklet on their wartime history/production,but have never seen one done by Norton,Ariel,Matchless or Triumph. The above and below adverts are from late 1945 issues of Motor-Cycling they give a bit of information on the Norton war production/effort.

BSA and Enfield were parent companies. I've never seen a publication covering Nortons and if it existed, it would almost certainly have had to be under the name of R.T. Shelley but they seem to have published little and perhaps deliberately kept the relationship between the group companies rather vague.

'in numbers of bikes made Norton are a close second to BSA.'

Don't forget this was before the trades descriptions act... ..
I reckon Norton wartime production was about 85-90,000 against BSAs 126,000....Ian

Ian, we're still finding odd batches of Nortons including the Australian contract that didn't seem to have been documented so there may have been more than we thought but I don't think there can be any doubt that Norton's claim must have included the pre-war War Office and India Office contracts.