Cool thanks ! Did you notice it not allowing the backrest itself to tilt down when you went all the way back to be firmly even on your back?

 

Moved back pad back two inches and down two inches. Used our press to extend the radius of the bend down until post was flat with top of seat then cut and welded.

 

After I did similar adjustments to my adjustable backrest, I was not happy with how it fit up thru the slot in my sundowner seat.
The easy remedy for that, if you encounter it, is to elongate the screw hole in the rear of the seat tab (Where it attaches to the rear fender) to make an adjustable "Slot" where you can move the seat forward or backward, then tighten down the screw and you are done.
It didn't take much, you can use a small round file - I used my dremmel tool.
I was concerned that without the rear seat tab slot adjustment, it might have damaged the upholstery over time of on/off, back/forth, and so on.
Remember - IT DOESN'T TAKE MUCH.