I have the privilege to know Bob Roller and would like to show five of his locks.
From top to bottom and left to right
Durs Egg, Durs Egg
Manton, small Ketland
The big Twigg is 5 11/16 long and 1 inch wide, the Durs Egg is 5 and 1/8 long and 15/16 wide, the Manton is 4 and 11/16 long and 7/8 wide, the small Ketland is the same as the Manton.
The Ketland has no frizzen Roller, but has the attractive early style hammer.
Manton up close
There is a roller on the frizzen and a cam hump on the spring
The Twigg up close
And the Twigg cocked
And the Ketland half-cocked and cocked. That is precision lock geometry, big and small
Copy and photos supplied by Heinz Ahlers.