Window pinch 4mm Allen bolts - where?

[AG Tuscan II S]

I found one of these butchered in my car which makes the window glass a pig to remove and replace.
Anyone know where to get one?
They have a massive chamfer on them - so not really standard AFAIK.

Also - in case anyone else has this issue - I managed to eliminate all the wind noises assiciated with speed by hours of careful fettling with the window fitment by moving the guide channels. Then I spent another hour or so making sure the windows were correctly seated in the pinch rubbers that hold them. Finally adjusted the window travel using the screw at the top rear of the winder chain guide. Non whistling ride now