I actually recovered all of my pictures from my phone that I dropped in the water, I will try to upload them soon. The pictures should make it very clear.
But, long story short, the bottom seat frame portion of the Recaros is the same as the non-Recaro seats except for a plastic bolster piece that is riveted on and obviously any difference between the focus vs fiesta mounting rails.
If you have a Recaro from a FoST and a non-Recaro from a FiST you can convert to the Recaro seat with regular hand tools.