Worn bushes on canti brakes

[Shut Up Legs]

The top-pull canti brakes on my Vivente World Randonneur touring bike that I use for commuting have worn out to the point where the bushes (I think?) aren't flush with the rest of the brake parts any longer. On both the front and rear brakes, applying the brakes causes the brake shoes to wobble backward and forward, which doesn't exactly help the braking action, and makes the braking a bit noisy also.
I've done well over 100,000km on this bike now, and these brakes are the 2nd for this bike, and I'd like to just replace a few parts on them, because replacing the entire brake assembly seems like overkill (even though that's exactly what I let a bike shop do for the 1st pair of brakes on this bike).
Is there any way to replace the worn bushes (or whatever else is causing the wobbling)?

The brakes are these ones (this photo is taken 6.5 years ago when they were newly-installed):

 

[Ajax Bay]

Have you already taken them apart, cleaned, greased and put them back, and tightened? If so could you see evidence of that wear? Have to say, with that usage and 5+ years, a new set seems a kind present before Lent, if the above didn't/doesn't sort it.