Kickstart shaft

Which gearbox ?

Are you talking the kickstart end of the layshaft or the kickstart shaft itself ?

On the later boxes only the layshaft at the kicker end is scrolled and the kickstart shaft is plain, looking at Andover Norton's drawing of the Laydown box it is the same. The kickstart shaft only rotates in the cover bush when you kick but the layshaft turns all the time so that makes sense. Sounds like a DPO mod that will create a leak. 

Hopefully someone who has been inside a laydown box can confirm.

That needs to be answered by someone with knowledge of the Laydown, maybe if you post in the singles section or the heavy twins more people will answer.

This thread is in singles

https://www.nortonownersclub.org/node/13425

and is asking about the Laydown gearbox.

On the first gear I would look at the inner cover, if the mainshaft support bearing is recessed like it is on the AMC gearbox then the shoulder is outwards so both first gears mesh fully and to stop the mainshaft first from chewing away at the cover.