I have done a deep dive into this. The Jacking Instructions label on our LM Corvairs mentions a screwdriver as part of the tire changing accessories if we have the simulated wire wheels. However; as far as I have been able to learn, no one has this screwdriver. I do believe that the screwdriver was intended to be a Vichek/GM straight blade. I have come to this conclusion based on the tool kits that were offered for many GM models around that time. In the image below, you see the screwdriver image tucked into the scissor jack and the screwdriver is mentioned in the WHEEL REMOVAL note.
Hi–my ’66 Corsa convertible (Willow Run, June ’66 build) had a screwdriver tucked in with the jack when I bought it in the mid-’90s. I am the third owner. AFAIK, it’s original… (I sent Doug a picture of it via email. Can’t attach pictures to comments.)