I have wooden awning windows (top hinge) that open and "lock" using a
central lever. Thus, unless this 6 hole lever is locked onto the
locking screw, the window is not fixed. There is no actual lock on the
lever/screw mechanism and thus, I am interested in replacing these
levers with a secure firtting that allows the windows to be opened in
fixed positions.

I hope this makes some kind of sense as it is hard to describe without
diagrams. The upshot is I am after a central locking system that allows
the windoes wo be opend and held in fixed positions.

Any ideas?

Cheers

Mark