The missing manifoils... 1,2...5,6,7?
I've recently become interested in the Chatwood Milner/Chubb Manifoil series of locks. I've already got several in my collection and I'm trying to search for _any_ information at all about the possibility of a Mark 5, Mark 6 or Mark 7 Manifoil existing or ever having been produced.
For those that are maybe not so familiar, the Mark 1, Mark 2, Mark 3, Mark 4 and Mark 8 Manifoils all existed at some point and examples are floating about, but i've not been able to find any information about the others.
I'm not sure if Chubb did a Microsoft Windows thing and decided to skip some numbers 'for teh lulz' or if they've just never been released to the public.
The only other theory is that perhaps they were never widely installed similar to how the X-08 is a lot less common than the X-09/X-07's are because of some hardware issues.
If anyone has photos of the housings and internals of any of the Mark 1 or Mark 2 manifoils out there, please feel free to add those to this thread too. As I understand it, there might have been different versions of Mark 2's out there.
Cheers!