I have confidence in my yard and this was its advice:
After a lengthy discussion with Helmut; Helmut would not suggest strapping or banding the hull/keel join with fiberglass, as any movement of the keel would cause this strapping/banding to eventually fail. the only other option we can suggest would be to try and torque the keel bolts, in the hope that we can minimize the opening between the hull and the keel, requiring that we remove the keel bolt covers that you have installed. We would then grind a "V" along the hull/keel join and fill the "V" with a flexible epoxy, in an attempt to seal the hull keel join. This is in no way a guaranteed repair, this may be a short term (a couple of seasons at most) solution to prevent water from entering the hull/keel join and corroding the keel bolts. The epoxy filler would need to be inspected every few months, to ensure that the epoxy is not separating from the fiberglass or lead and allowing water to ingress into the hull/keel join.
The only real solution to repairing the hull/keel join would be to remove and re-bed the keel, at the same time the keel bolts and the sump/keel grid structure should be fully inspected. If it is your intention to keep the boat for another couple of seasons then consider the first option, If is your intention to keep the boat for another four or five years then I would urge you to re-consider completing the keel re-bedding.
As for the crack not looking too bad, to me the fact that the keel was rebedded in epoxy meant that any crack was a structural failure.