Neck Angle and Set
The neck angle and how deeply the neck was set into the body has changed over the years. The earliest examples have a vry shallow neck angle, fairly depply set into the body. By 1964, the angle was greater and the neck was set less deeply into the body. You can see this in the pictures at the right. Note the difference in the height of the pickups relative to the pickup rings. This is necessary due tho the difference angle and set of the necks.
The last picture shows the neck tenon on a 1961 ES=335. The shape and length of the tenon was quite consistent throughout the Golden Era.