There were No.1s (Shot, Magazine, Lee-Enfield). No.2s (.22 trainers, two different types - one being a purpose built trainer and the other a converted No.1 to .22). No.3s (being the P14). No.4s (Mk.I, Mk.I*, Mk.II - also the conversions Mk.I/2; being a Mk.I upgraded to Mk.II standard, and the Mk.I/3; being a Mk.I* upgraded to MK.II standard). And the No.5 'Jungle Carbine".
There is no No.6 rifle.
The No.7 is either a converted No.4 to .22, or a purpose built .22 training rifle that looks like a No.4. The No.8 is a purpose built No.4-esque .22 trainer built for New Zealand - but with cut back wood, and a shorter/heavier barrel. And the No.9 is another .22 trainer built for New Zealand - but it appears in more "proper" No.4 like form.