I've worked on a few Compur shutters in the last ten years. I've tried a few easy fixes, and one or two of these has worked. The easy fix was merely to soak the shutter in lighter fluid overnight, slosh it around a bit occasionally, then dry between two pieces of paper towel. This worked twice. Just so you know; it can take a day or two to dry thoroughly!!
The best job is to completely disassemble the shutter, taking the shutter blades out. (making it somehow that you put them back in the same place later preferably.) I then clean the blades individually with pure alchohol. Put the shutter back together the same way as you took it apart and make sure everything is as clean as you can make it.
The shutter blades are ferrous so they can easily become magnetized, so you may want to consider this. I use a tape head demagnetizer. I do not use lubrication on the shutter blades anywhere but I have on one occasion used a bit of soft pencil (graphite) on the pivots. Go easy on the graphite as it can work it's way to the lenses.
The other areas like the escapement mechanism I use a fine watch oil like Moebius (
http://www.ofrei.com/page246.html) applied with the tip of a toothpick. The main shutter spring I use stuff called Nyoil (
Dead Link Removed) applied sparingly.
I think in many cases it would be nice to have a new shutter spring but I don't know where to find such things for small shutters. I anyone has a resource I'd like to know of it.