Tricky. If you want to absolutely avoid detail loss, you'll have to use selective leveling and blurring.
1st leveling layer 90:1.2:236
2nd leveling layer (above the first) 0:1:245
Smart Blur, 5:10, Low, Normal
Then look for the pages where the gradients have fading edges. Restore the edges from the backup. Then paint black on the second leveling layer to restore the loss through leveling. Paint far enough into the gradient so the contrast between painted and unpainted isn't obvious anymore.
Hope that makes sense. Here's one example.
http://www.mediafire.com/?deed8n9a369892g