I've never found a seller with boxed identifiable genuine inlet and exhaust guide pairs and there were numerous post-war pattern suppliers. It's also quite possible that the War Office were obtaining from alternative sources after the war so even an LV7 label is no real guarantee.
If you Google "Norton 16H valve guides" you'll be reminded that we had a discussion about the possible differences between in. and ex. guides about 10 years ago !
Unfortunately, along with photos, I can no longer post links on this message board.
Thanks Mark but the reason I asked is because I came across about 30-35 of them (and some inlet valves)...Since my post I've looked on t'internet and there are a few vendors selling them, so at this point in time I think I'll leave them where they are!....Ian