A New Factory Western A-Frame for the back of the later Pro and Midweight blades. This is the same for Steel and Poly. The part # on this A-Frame is 68291. This bolt to Quadrant 68290 with bolt 69494.
Make sure you compare it to what you have, the early Midweights used a 28592. The 28592 is hollow in the A of the frame and the 68290 has a bar welded across the A part. Another way to tell is the 68291 Aframe uses the 1" Bolt and the 28592 uses a 7/8" Bolt.
This has a hole in the front for a 1" bolt, part # 69494.
The cylinder holes are for 1" pins.
The opening in the front inside measures 5-1/8"
From the flat on the back of the a frame to the front tip measures 27-1/4"