Sterne Viper Keel Placement.

I am mounting a keel on a Sterne Vemom Marblehead, and I am a little unsure about keel placement in the fore & aft direction.

There was a five inch line on the bottom of the hull running stern to bow.
The boat has a line running perpidicular to the Fore & aft direction about 2 inches forward of the stern (not centered)
It also has an oval running forward.

Given this, where am I suposed to mount the keel?

Where should the center of gravity be on the bulb given these marks?

I included a couple of pictures to try and help adress the issue.
Keep in mind the picture is not to scale, and the crossing line is 2 inches from the stern (doesn’t appear that way in the paint image)