The factory seat in my kayak fits me, but is not the most comfortable so this is where I will be starting my customization. The backband is one of the smaller IR ( Possibly and old “Reggie”) and I have ordered a new IR “LoungeBand Backband“. Its a little wider, and a little taller. That should help my lower back support immensely.  In addition, I removed the factory seat which consisted of a molded Kydex bucket and a rather firm spandex covered pad.
When installed the seat tips upward at the front by means of a minicell block glued to the floor and seat. The side of the bucket is pop-riveted in-place but two of the rivets were missing and so the seat came off as a bit shaky.  I have posted some pics of the disassembled parts  here.