My brother has a Cape Charles 17. You can make a simple keel strip and fasten it to the stern area. It only has to be a piece of hadrwood about a half inch wide that tapers from nothing to about 5/8" high. It should be about 2 1/2' long. You can do a trial by fastening it with the electric glue gun to the stern area. You can always shave it a bit if you want. then Epoxy it in place and blend it into the boat. Pretty simple and it will work perfect.

No sense going through all that skeg box stuff.