Hey, this is getting good LOL
To be honest, I was thinking the same as Paul, broken pallet stones, that was my first thought as it isn’t an uncommon occurrence, but now the shadow of doubt is looming over me noggin 
I haven’t looked at this movement either, because it only arrived yesterday, so with all your great participation and possible cause suggestions, I may have to do a quick strip, because now I’m curious too haha. Problem is that my area is full of mill parts.
Paul, what are you talking about coming to see me to learn watches? Looks like I should come and spend a week with you dewd LOL