One of the flap skins was slightly damaged so I selected left/right flap skin based on cutting off the damaged portion as scrap.
After confirmation w/ Kerry from Sonex, that the upper & lower Inboard edge dimensions differ, I needed to trim the upper inboard flap surface as the length as measured from the outboard edge is slightly shorter than the lower inboard edge. I had initally cut them to the same length. Luckily for me the upper edge was shorter than the inital cut!
After the edge was trimmed on each flap skin I resmoothed/resanded them.
Next, I measured, cut and sanded the flap drive cut-out on both flap skins
Damaged section on scrap side of cutline
trim and sanding complete
drill location for rounded corner of flap drive cut-out