The later model collapsible columns had a plastic pin poked in the shift tube ( until 68 when reverse lamp switch moved from shifter to the neutral safety switch ). I put a link to that plastic pin in a similar thread just a few days ago. Here is a pic of the correct part for your 65 model....
[WANTED] - Back-up light pin actuator for 1965 Dart
If google search or parts wanted here doesn't produce one, If you'll have to make a different attach/hole either way you may as well put a small bolt in it. Other owners/members have done that. They may have had to take the column apart, remove the steering shaft to get a bolt in there.
If I was going to attempt this, my 1st effort would likely be what is called a closet bolt. It holds a toilet to the floor flange. The thin coin like head could be radiused a tad to lay to the inside of the shift tube. Maybe one edge of it turned up 90 degrees too?
