Asi, not at all. Far be it from me to make accusations, I'm here to learn as much as I can so I appreciate any insight the veterans of the forum have to offer on the subject.
In addition to the aforementioned article, while searching for more information about OP case subcontractors, I also found several mentions of yet another company that was supposedly producing PreV cases alongside Valgine and Coro- QUORUM Ltd.
Here's the thread that mentions this third case maker, it appears that member PoyFR has quite a bit of interesting, I would even go as far as to say insider information about OP's business during those years.
http://panerai.watchprosite.com/?show=nblog.post&ti=510491
Also, most have probably seen his 218 writeup:
http://panerai.watchprosite.com/show-forumpost/fi-717/pi-4122856/ti-655381/s--23/