On my 69 gs the key has to be rotated all the way before starter is activated. I sort of remember switch connected by a linkage but it was a long time ago. Is there an adjustment ?.
I think the switch part is on top of the steering column. The key is on the column on a 69, unlike a 68 where it is on the dash.
The ignition switch is on the column, on top, at the firewall. There is a small amount of adjustment, with a couple of screws to loosen and re-tighten. If that adjustment doesn't fix the problem, you may need a new sector gear or the rod. The teeth on the sector gear and rod do wear out.