Wrong threads on the caseback

[Vonn]

Has anyone ever had this problem?
I got three solid casebacks from Getat that are supposed to fit on the "new" 44mm case, which is a 44mm bettarini Luminor case.
The casebacks fit neither my DSN 44mm, my other 44 Lumis or my Mini fiddy case. It appears to be about a millimeter or 1.5 to big in diameter
Any idea how I can fix this problem? If it was a bolt I would just use my three steps thread-cutters to adapt its size, but this is something iike a 38x7.5 thread or so and I have never ever done something like that, nor do I have an idea where to go to, to get this fixed.
I will go to a business called "Werkzeugmacher" which translated to toolmaker, to get the cases drilled and threaded for the NW crown tubes. They usually have all the lathe, mill and cnc stuff for little tolerances like we need, but I doubt they can cut a thread that small in height.
Really sucks because at the moment Getat is the only one who has gen spec (referring to design) solid casebacks for 44mm cases.

I'm a little lost here, so any help is appreciated!

Edit: cutting a new thread in the cases would be my last resort. One of them was supposed to go on a gen 111, so no way I'll be cutting a new thread in this case.

[Vonn]

Any Idea how to fix this?

[Emilio]

Contact Joe (Neckyzips). He has access to dedicated machinery.