Zodiac "do not open" barrel

[limpnoodle]

Hello, I just started in on my next project which is a zodiac aerospace gmt. When disassembling the movement (zodiac caliber 75) I saw that the barrel says "do no open" on it. Has anyone had any luck attempting to service one of these barrels? The mainspring definitely needs some work but I don't want to risk damaging anything without being able to source a part. Any help would be appreciated. 

[nickelsilver]

From experience, I've been able to open all "do not open" barrels and close them except Zodiac. The ones I've seen are truly crimped/burnished such that the cap is destroyed in removal. Last one I did I made a new cap.

[Nucejoe]

If the watch is a keeper, Swtich over to removable lid type.

Regards

 

[limpnoodle]

Unfortunately I do not have the skill yet to create my own lid. I decided to clean everything up and to hope for the best with a 60 year old main spring. Surprisingly the amplitude is not terrible! For now I think I'll leave it be and try to look for a replacement.