Side Scales
However you decide to service the shutter make sure you remove the printed aperture/shutter ring because if you stick that in a white gas bath, in an ultrasonic cleaner, it will remove the writing. I have redone some shutters. One Compur Rapid from a Rolleicord, and Agfa Isolettes, and Agfa Record shutter. You need the proper tools to do it right. Precision German Screwdrivers, and other tools. If you can find someone to do it that does it all the time then it's worth getting it done. Also, if it's a bellows camera, then email SandehaLynch.com and have him build you a new bellow. I do this to all of my folders. Bellows are the weakest link in these great systems.
Greg
P.S. Here is my Flickr Album for Shutter work.
https://www.flickr.com/photos/kb2qqm/albums/72157651667174417
The Compur Rapid shutter is a pain in the ass, because there is a self contained shutter timing escapement that hinges from inside the shutter either closer or farther away from the lens barrel, which either makes the shutter faster or slower per the shutter settings. These escapements are very old and sometimes the coiled spring is rusted so really it's a waste of time. If the camera has been a closet queen and it's in great shape then maybe its worth it. The 1/500th setting is set by a separate spring. I much prefer the Agfa shutters. They are easy to work on.
Here are some photos of the Shutter and Timing Escapement gear. I am sure your camera is close to this...
the last photo shows how much gunk that came out of the shutter. These types of shutter are like 50 and 60 years old and need a proper tear down to really get them running like new.