Junghans MEGA Radio Controlled Watch, ca. 1994

Luckily the scratches left from opening are not deep!
The slipping case opener marks left are not deep at all. The problem with this specific case back is that the opening groove at 12 o'clock is small. Another problem is that the case is curved upwards at the lugs and that reduces access to the opening slot further. I still managed to open it, with some scares and opening marks. I really hate when that happens, especially to a watch that is opened for the first time! Slipping once is bad, slipping twice is almost unbearable for a WIS (watch idiot savant).

They are somewhat exaggerated in this picture, a reminder for me, to more carefully choose the openers the next time. First I had tried the Bergeon 4755 (the one on the right) - but the groove in the case back was too small for the opener to grip firmly. I slipped and left the first small scratch on the back. I then tried the A&F case opener knife and slipped again, this time leaving the second scratch on the case back.
Finally I remembered that small and practical MKS Case Opener (the one on the left) and this one did the job with ease! And because the scratches were not deep, a little bit of buffing with Crystal Clear (an aluminum oxide watch polishing paste from www.watchpolishing.com ) removed them almost entirely.

This stuff is really quite amazing. A light buffing for ca. 2 minutes witch "Crystal Clear" got rid of most of the light scratches! I am happy again! Well, as a WIS I will never really be able to forget, but at least the opening marks will not jump into the eye anymore.

PS I am not affiliated with www.watchpolishing.com. I had once received a trial sample of their polishing paste and have since put it to good use many times. There are plenty of watch polishing pastes out there, Crystal Clear seems to be one that is fit for many different applications (metal cases, crystals etc.).