I was thinking of a different way to do this so that it would work more like a 2005 Vette where no metal key is required at all.
My thinking is to work with the existing switch and wiring for reliability and ease of service.
Since my 69 Vette does not have a dash mount switch (68 would), I thought of the following.
Installing a Linear actuator (
www.uslinear.com) on the steering column set up to push the ignition switch forward to the run position when you activate it with the keyless entry remote (option 1). Once this is activated the car is ready to start. I would run the START ENGINE button in the steering column mounted flush in the stock metal key ignition switch lock housing. It will still be wired through the alarm and neutral saftey clutch switch. In other words you would have to be in the car holding the clutch to start.
To turn the car off I would activate the Option 1 button on the keyless fob. This would trip the relay and cause the linear actuator to move back releasing the ignition switch on the column.
Because it would be tied to the alarm, simply breaking the actuator out and manual moving the column switch forward would not allow the fuel pump and ECM to go active so the car might spin over, but not start.
Still hammering this out in my head, but I think it will work.