Circlips are a b*****d to get in. As has been suggested elsewhere on the forum, invest in some mini, needle-nosed, locking pliers. Get the first bit of the circlip in, clamp it with the pliers, then shove the rest of the clip in. Once it's all in the tube, carefully manoeuvre it down into the recess by pressing evenly on each side whilst preventing it springing back up. I almost lost a fingernail before I knew what I was doing.
As for the bushes (done 12 years ago), they would not go in when new. Honed out the sliders with sandpaper on the end of a long piece of metal rod attached to a drill. When they did go in, it took several thousand miles of riding for them to work properly. Last time I looked, the bushes had a lot of scoring on them, but work fine. Maybe the scoring helps oil to seep past and lubricate them better, who knows.

Quick thought, would the scoring contribute to the seal leaking??
The l/h has to come off soon to replace the seal again (fourth time). The r/h hasn't leaked in the 12 years since they were built.
Apparently, when both the forks are built up with the wheel on, one should leave the clamp bolts on the wheel spindle and mudguard fixings loose and bounce the bike a few times. This 'centre's' everything up and settles the stanchions/sliders in the optimum position.
If I've dreamt this, I'm sure I will be corrected forthwith.