So we found this 60's camera hiding around with old things. I found that it had a problem with slower shutter speeds, the shutter and the curtain gets stuck. By googling, I found out that it actually was a common problem. Most pages point to oil drying out. I didn't think sending this out for a fix was worth it, so I decided to fix it myself, following my "it's broken anyway" philosophy.
Warning: You could permanently damage your camera, and it will cost more to repair your attempted repair. Also, the very small parts inside the camera can seriously injure you, specially your eyes. Do this at your own risk, I will not be responsible for whatever happens to you or your camera.
Just remove the plates on the bottom and the front. Lightly put oil on the parts highlighted with orange below.
Once greased, fire the shutter a few times to spread the oil. You can also try adding more oil on the gears. Just estimate how much oil it needs.