Benny’s assumption due to dual swing keels is a British design. The suggestion to inquire with British forums is suggested as this is more toward American made boats. I as a former dealer do not recognize this boat.
There is no question that the top of the swing keel needs to be removed and repaired. Getting it out is the question.
As for the keels, generally on the British designs were pulled up via cable or line but cannot be sure. Who knows it could be spring loaded but not sure that is the case. The picture of damaged keel does show an eyelet on the backside of the keel as if something like a line would be attached to.
It would be helpful to take pictures of the inside of keel housing to see if there are any holes in the upper part of the housing for lines or cable to go thru. second a photo of the interior cabin looking aft would be appreciated along with a photo of exterior cockpit.
Generally American made boat keels are attached in several ways. First a pin running through the head of the keel held in place attached to hull with bolts screwed into metal encased in the hull for example Catalina 22 and 25. Sometimes the line comes up thru a fiberglass tube which is above the waterline. Secondly, the keel could be held in place in a bracket keel bracket housing like the water ballast Hunters bolted within the cabin but removed under the hull. Third, I have seen swing keels held in place via bolt through the keel housing above waterline with neoprene washers to prevent water coming into cabin. Once I saw bubble gum used instead of the appropriate neophrene washer.
Can you take a couple of photos under the cabin floor to actually see what’s there? Do you think repairs to hull were made on bottom of hull adjacent to keel housing area? Maybe a picture or two looking toward stern and one toward bow?