Got a e-flyer from Coventry spares..
Listed is a 72058 bearing for the steering neck on commando.
WELL! No such thing...
This basic bearing 7205
B 2RS was used for a very short time by norton on early "S" commandos, This bearing was discovered by one original "S" owner.
While the cheaper cup/cone & balls were the predominant choice during S1 Commando era, probably for cost reasons, Norton settled for 6205 2RS for series 2-on commando. The 6205 has a slightly reduced static load capability from the 7205 but for the price differential it seemed like the way to go.
A little research shows these 7205 bearings at about 5X the cost of the 6205.