[Rory McNeil]

On older cars that were made before self adjusters were used, the adjusters had much larger peaks on the star wheels used for adjusting the brakes. The larger space between the points allowed the lower shoe retaining springs to grab the star wheel tighter. You may still be able to buy the early style adjusters new, maybe ask for adjusters for something like a 57 Chevy , and see if they are the same length.
On my Mustangs rear drum brakes, I when I got rid of the self adjusting stuff, I cut down the female end of the adjustors enough to allow a jam nut to fit. Yes, you do have to remove the drums to adjust the brakes, but as long as the jam nut is tight, the brakes will never mysteriously adjust themselves too tight.