Hi,
I had a similar experience, but it was not a cored hull. In my case it was on a '66 Columbia 24, but the same thing had happened - she had been improperly blocked and ended up with 4 pushed in areas where the pads were. It was actually rather severe, and I didn't realize it until first haul out (bought her for a couple hundred bucks, so didn't know until after purchase, as hauling to look at her at purchase would have cost more than I paid...)
So, what to do. In the case of the Columbia, it was a solid layup. I made ribs out of 1.5 inch PVC that was ripped length wise and then partially cut cross wise so it would flex to match hull contours. These pieces of PVC were placed about 4-6 inches apart depending on the location (ended up running them down the whole side of the boat basically). Then I put fiberglass tape over the ribs, placed plastic sheet on top, and then long planks on the sheet, and then jacks were used to push the planks out which pushed the ribs out, adjusting the jacks until the right contour was regained, and then allowing the taped ribs to cure. After this initial taping was cured, the jacks, planks and plastic were removed, and then I came back with more layers of tape over the PVC and then very large layers of cloth spanning across the ribs. I think I did two layers of tape per rib and 4 layers of cloth - giving each rib 6 layers of glass when done.
The above process got the hull back to its basic correct shape, and it was rock solid. The big variable here though is you mention a cored hull. I was not aware that the E-34 was a cored hull, but I am not an expert on all the hull construction methods Ericson used. I don't know if you can push out a cored section like I did. What I can say is that my dimples weren't returning to the original shape, and as I dug into this, I had to make the assumption that the flex had damaged the glass fibers, and that's why it wouldn't return. I would be concerned that you have lost some fiber strength in these areas, and I would be compelled to do something that added strength beyond a fairing compound. I might be tempted to approach repairing these areas like you were glassing in a hole, so you would fill the indentations with cloth, not filler. I would also be tempted to do some layup on the interior side that extended out beyond the dimples a foot or so in all directions.
Hope some of the above helps.
-David
Independence 31
Emerald
p.s. as I was writing this, I see that Steve responded with his experience where they filled the dimples with fiberglass, which would match my thoughts of approaching this like they were holes you were repairing.