The drawing can be slightly out of measures due to copying process.
Important is, that the temporary tabs (green arrows) are fitting into the notches of the bottom of the jig! The complete ship construction with all frames etc. will be based on the correctness of this jig. So check this.
A slightly lengthening of the keel can come also by the sum of the three joints of the keel (red arrows) - Did you remove the laser char inside the joints?
Important will be the location of the frame notches on the keel (parts 10-6, 8-1 and 10-3!
But I had here also a slightly difference in length
which I left and closed with a small piece of wood, so that it is not visible - but the length is slightly wrong also in my model
You can also check the length when you compare the notches in keel with the notches in the keelson (without frames) - they have to fit also (especially part 10-8
I have missed this thread until now. Is your drawing the original or a photo copy (looks like a copy)? I tried making photo copies on a rather expensive machine at my work but I had to archive the copies vertically in the trash bin as the copies had shrunk around 0.5% compared to the original