well a syncro issue would show up by it not being so hard to get into gear and a loud crunch if you change gear at a speed where the syncro would be needed. i know i have a car with a dead syncro on 2nd. crunches if you drop to second at 30mph, but not at 20, otherwise its fine.
replacing all of the clutch should probably cure it, there was wear on the spring forks ? that wear would mean the bite point would raise, making it less likely to disengage fully.