Aries Repair, a set on Flickr.I replaced the delrin bearings on the servo paddle shaft. The most scary part of this job is removing the pin that the shaft hangs from.
The 'rebuilding tips' page from the Aries vane gear contain the following instructions:
"Lay the Vane Gear down flat on a concrete surface; place hard blocks close to either side of No 59. Find the largest sledge hammer you can find and with an appropriate 'drift' give No 59 the hardest blow you can manage. Avoid light taps as this swags out the end of the shaft."
It took me a day or two to prepare myself psychologically. But it did work.