Bolted in the WD-409 to the F-711, set the torque and marked with TorqueSeal. I noticed this left a gap at the top of the aft face of the 409 where it met the F-712. Did some reseach and found several people who had similar issues, and the recommended fix was to make a shim to fill the gap.
Did some measurements of the gap and made a rough sketch of what I intended to make. Needed about .065 to fill, so used two pieces of .032. Did the initial cut out from some scrap sheet aluminum.