best i can do mate. Looks like they do have a pyrotechnics charge inside the reel after all. This was taken from the rear, so it may differ on the front, sorry... not as much help as i thought. Can't dismantle it anymore than it is, as there are warning of explosion all over the covers lol.
think it might be a new unit needed, as it is impossible to rewind this thing. Like i said, if you are replacing... don't buy new if it can be helped, they are a ridiculous price