In case anyone is interested, I have some mild success to report...
I went to Harbor Freight last night after work and picked up six of the tiny bar clamps they sell for $1.69. I cut up some wood shim and clamped shim on the spokes to flatten out the pad. While clamped, I cut out the bad foam from around the steel inserts. A hot-knife did not work well, so I just used an X-acto blade. Once those cavities were exposed, I injected silicone into the pad and leveled it out flush with the back edges. It is still curing but it is looking very promising.
I haven't attacked the center section, but I'm thinking that the same approach will work.