When I assembled the keel way back at the beginning of the build I thought it would be a miracle if the the pre-drilled port and starboard holes lined up exactly.
I was right. First I drilled the starboard hole, as here.
That looks OK, but when I drilled through and out the other side this is what it looked like from port.
First I enlarged the misaligned hole with a rasp, like this.
Then I filled the hole with thickened epoxy and clamped a couple of plastic cards in place to retain the mixture. Like this.