As Nick alluded to, installing the rigid plastic strips were easier before the bottom was hog ringed in place. I didn't have to remove the rubber bottom to do this. Because there were 3 holes in the strips, I opted to use the zip ties and stainless steel washers as well, as I figured they will help anchor the strips in place and fill in the holes in the seat bottom.
Before:
image.jpg
I applied leather conditioner before and during the pulling and stretching process:
image.jpg
Here is the underside right side bottom cushion finished:
image.jpg
After:
image.jpg
This was my first attempt at upholstery work, so I took my time to try to install the skin properly, and I was pleased at how well it fit.
The upper half is next...