Eric,
Yes, I now recall receiving a sheet of felt. I found the firmness provided by that installation set inadequate (even after I doubled the cotton batting and the felt).
After looking at a
picture of a cross section of a seat cushion and studying
a photo album of Denny Graham's, I think that felt is not firm enough (and/or the thickness I received was not thick enough) to hide the tops of the individual springs. It seems that a matting firmer than felt (a coir material) was in the middle of the layers covering the bottom seat-cushion springs.
Here is a hijacked thread that discusses coir matting.
