Using the templates I have confirmed that this keel has not been templated with J/30 templates. The keel requires about 1/2 an inch (10MM) added to the leading edge. As you can see with the templates that creates a gap up into the maximum chord thickness.
The end of the keel about 1 foot from the trailing edge wasn't flat so it had to be planned down.
I only had to plane down the trailing end of the keel (using a power planer). The leading edge was left untouched as it will be built up using hardwood battens about 10MM wide and 5MM thick.
Same on the port side.