Originally Posted by CrankyFranky

I recall that there were two types of pushbutton adjusters.
The first (earlier) type has a small slotted set screw associated with each button sometimes under the button at an angle. You would tune manually, then push the button in and hold while adjusting the screw until you felt it touch a bar. You would then hit another button and then the one you just set to see if it tuned to your station just right - and if it didn't, you would fiddle with the adjuster screw just a bit until your station would tune correctly when you next pushed the button.
In the later type, you would tune to the station with the dial, and pull out on the button you wanted to set, and then you would hold the tuning dial while pushing the button in all the way.
At least that's how I remember it.