Thank you. I am no expert on movements, but while I know about the 'danger hours' for setting the date, I had no idea about this potentially damaging the GMT function. In fact, even now, I tried to Google this and it just doesn't come back as a potential issue for damaging the GMT.
I had been working under the assumption that the various issues and damage were caused by concussive impact on the watch/movement, and to be fighting for this for so long only to have a single line note on a quotation potentially sink my case is..... frustrating and depressing.
That package really looks terrible.. Having said that, it's very unlikely that that's in any way related to the behavior of the movement. As long as there is any padding covering the watch, even just a thin layer, transport damage shouldn't be an issue. Mechanical movements are super tough, they don't fail that easily. And even if, the GMT function wouldn't be the typical breaking point.
I watched a YouTube video on the FC-350 in the mean time, since I was curious how how that module actually operates. I hope you were aware that the GMT hand doesn't quick set through the crown like it does on other GMT movements (e.g. the Eta 2893)? The second crown position moves the
regular hour hand in 1h-steps, while the GMT hand is linked to the normal time setting. The date flicks when the GMT hand passes midnight, not when the regular hour hand does, which would explain the 4am date change.
Are you sure the movement is actually damaged, or maybe this is all rather a misunderstanding on how that type of movement is supposed to work?