I need some suggestions. I have a 1961 K10 short stepside which has ingition switch problems. The entire back phenolic piece with the wire lugs poped out of the back and the ignition switch spins around in the dash hole when I try to turn the key. I bought a new switch from NAPA number KS6175. Both the new and old switches have a "D" shaped shaft that goes through the dash hole. Part of the problem is that the clocking of the flat part of the "D" is in different locations. The new switch is about 5 or 10 degrees clockwise from the original. The biggest problem however is that the dash hole is now rounded and has no flat. Has anyone repaired their ingition switch hole to reform it into a "D" shape?
Dash hole pic

Switch hardware new on left old on right
Thanks.