Just a couple of notes re H-34 keel:
The keel has "ears" that stick out to either side of the main fin part so it is a lot more stable than a regular keel that is mostly bolted on centerline. Those ear flanges are recessed into the hull and the main structural grid.. The bolts embedded into the cast iron are stainless as are the nuts and backing plates. The bolts/nuts are not in bilge water so they stay pretty much nice looking. Of course, any long term leakage around a keel bolt can result in crevice corrosion, but the added stability that the "ear" flanges give to the keel makes leakage less likely.
In the picture where you can see two, the bolts are about 12 inches apart. also of note is you can see in the bilge picture "pocket" bilge in the hull.That is the shape that you can see the "crack" trace in his original picture. at the top of the keel. Does he have a significant problem? I can't really know but I'd wager that the keel is OK BUT he needs to carefully look at the chainplate attachment angle iron anchors that are mostly concealed in the structural grid.
Here is what my keel bolts look like after 40+ years:

