G'day Batimus
That's my reading too.
The model 31 came out with the Walter Barr jobs, and the
Model 22 kicker appeared in the same year ... 1958.
The repaired wheel is from an earlier 22.
It's typical that the nylon bush wears the axle, not visa-versa.
The reason, as you say, goes to poor sealing and dirt ingress.
The softer material (nylon) embeds dirt to abraise the harder steel.
I feel Pope offered the best wheel seals in the day.
I have covered the patent somewhere on ODK.
It may be that the Walter Barr wheel, being semi-pneumatic,
have just contracted a little with age and rubber deterioration.
Anyway, it's great another SB Model 22 has been documented.
Cheers
Jack
