The other issue that really really slowed us down was delamination of the gelcoat. We'd sand down to the primer on the hull and see little tiny blisters. So we'd sand down through the primer to the tiny blisters and they'd flake off. All of the gelcoat in these areas had to be removed, all the way down to the glass. All of the areas of exposed glass need to be epoxied and sanded - three coats. This also took a long time.
We should have removed all of the gelcoat from the hull, to be safe. But this is not meant to be a 20 year repair job, only a 10 year job. This is a 30 year old boat, and I don't expect to have it more than a few years.
This photo was taken a few nights ago:

This is the keel, repair completed. I put an extra layer of 1708 just for added protection. I really doubt that it needed it, but it helped my confidence about my repair work. The repair has been faired and will be unnoticeable after painting. The repair is rock solid and I have no concerns about its structural integrity. Another nice feature of this boat is that the keel is a sealed enclosure. You can punch a big hole into the keel and the boat won't sink.