You'll need to find a cylinder that will accept the ignition key blank. Re-building the cylinder to the same cut won't get what you're looking for.
If you try, you won't be able to insert the ign key into the trunk cylinder and the trunk key won't slip into the ign cylinder. There is a rail in the cylinder that the key rides on.
I'm no expert, but I don't think a cylinder like that is out there.
