Thanks Mitch.
So so if you do like I said and follow the figure and line up the rivet holes on the bottom it works. Fig AF-AF is wrong where it gives the 2.25” measurement when following the Figure 51 to align the holes with the rest of the ribs. Following Fig 51 aligns the rivet holes and still gives the edge and cut-out clearances. All good then if you ignore that 2.25” measurement given.