For the 1967 model year, all GM passenger cars had first generation, energy absorbing (EA) steering columns.
For the 1969 model year, all GM passenger cars (except the Corvair which ended production that year) were equipped with second generation, energy absorbing, function locking, steering columns.
Pickup trucks and vans did not receive the energy absorbing columns until several years later. This is probably why the steering column in Rodder's photo has a rigid (non-EA) column even though it also has the 1969+ turn signal switch with the "harmonica" type connector.
In 1973, conventional light duty trucks with automatic transmissions were equipped with the steering column locking system.
In 1979, the steering column locking system was expanded to the remaining conventional light duty trucks except G-van models.
In 1982, the use of the steering column locking system was expanded to the G-van.
I was under the impression that the four way flasher was required starting in 1968. But maybe it was 1967.
I am sure that the key warning buzzer became standard on all GM passenger cars starting the 1968 model year. (1968 was the last year that the ignition lock cylinder and switch was mounted on the instrument panel.)
JIML82