I used stuff from http://www.colourlock.ch/ to R&R the seats in my '68 S-Type.
I started with this:
Planning a patch:
Patch “backed”:
“Topping” a patch:
Filling the edges:
Almost ready for paint:
Painted:
Yes… that is the same seat squab.
It’s pretty much the same as doing bodywork and paint. The “Liquid Leather” can be used to fill the gap around a patch, or to smooth out a crease mark.
… But it’ll take more than a couple of beers and an afternoon on the porch.