I hadn't known until recently that Corfield made cameras (and other equipment) in Ballmoney, Co. Antrim. They moved there from Wolverhampton for various reasons, all made pretty clear on the website corfield.org .
I have also found
this link to a short film made at the Ballymoney works. As the entire sequence is shown twice, it is only about six and a quarter minutes after all; but it does illustrate a very hands-on approach to camera manufacture. They're making Periflexes, of course.