Metropolitan Railway lever frame
From around 1889, the Metropolitan Railway built its own lever frames. They seem to be a crude copy of the Great Western's designs, for some (bit not the one illustrated here!) had raised tread in the quadrants between the levers.
The frames were of simple construction, and embodied tappet locking.
None survive in use.
This example is at Wendover, more details of which can be found in the Photo Gallery.