That is probably the root of your issue right there if it is true.
In '67 and '68 the ignition key slot was in the dash. In 1969, many car companies adopted a theft deterent system where the key was in the steering column. Locking the ignition also locked the steering column and the transmission selector.
The way they did this with floor shifters was to leave the rotating sleave for the column shifter still there, but they locked the floor shift through a series of linkages from the column to the floor shifter.
So if you truely have a '68 column transplanted into your '69, you have issues. But I doubt it because you noted that you have the rotating sleave.
So is your ignition key in the steering column?
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI