Llewellyn Cadenzia Double OS Horizontal Single Taper Lugs-Mild Steel
Here is Darrell's description of the lugs:
"The “Cadenzia” lug set is a joint design project between Italian frame building legend Dario Pegoretti and me, Darrell Llewellyn McCulloch. Released in February 2009, these are the world’s first road bike lugs for XL/DOS tube sizes with a level top tube.
The lug set sits alongside the Llewellyn XL/DOS Compact lug set, so a builder can design frames with a either a level or sloping top tube using XL tube sizes. XL sized tubing is selected for the tall or big lads to ensure the bike has the correct handling."
Socketed Seat Lug Option 2 (201302-3140) for 16-17mm Seat stays: https://www.cycle-frames.com/201302-3140-llewellyn-cadenzia-double-os-horizontal-socketed-st-lugs-mild-steel.html