Had a sticky guages problem myself... also my odometer was broken. Got a replacement from the wreckers, and 2 days later it broke
Out of frustration I ended up attempting a repair on my old one. Found the odometer fault was just broken mounts that hold the PCB in place on the speedo. Got some slightly longer screws and fixed that, the trick was getting the gears around the right way as they had fallen out.
Checked for dry solder joints, didn't have any. I put a drop of sewing machine oil (really thin stuff) on each of the guage needles - where they pivot. Not sticking at all now, although the only drawback is the speedo doesn't drop below about 5km/h - although it appears accurate. I read some rubbish that you shouldn't touch the guage needles - whats wrong with doing this as long as you don't put a great deal of force into it and only move it along the area its supposed to move? I moved each of the guages around to work in the oil