When '69s get like that they are beyond saving. You can mess with them a bit; trim the edge of the liner and re-glue the pad but it will continue to shrink, harden and curl. 42 years is a long time.
The GM service pad didn't look the same as OE and had a bald spot where the grain had worn off the tooling so NOS isn't the greatest either. I hear the latest repro is nice. Don't waste time and money on an original.