Is it possible to upgrade/convert the 'cup and ball bearing' headrace for taper bearings with a spacer similar to what you are able to do to featherbed framed bikes.
I have done it on my N15 ang G15 using the commando bearings.I haven't done this myeself (yet), however all bearing parts and the crown/stem are identical, thus it should work. Bearings are available from numerous sources, e.g.
https://www.feked.com/norton-steering-head-bearing-conversion.html
-Knut