The Brazilian rosewood fretboard was first used on the Jazzmaster in 1958, and became the standard on Stratocaster and other models from 1959. Until the middle of '62, the gluing surface of the neck and fingerboard was a flat "slab board", but after that, it was changed to a "round board" with a curved gluing surface, which greatly affected the sound.
The early slab models had thicker fingerboards and a thicker sound.

In the middle of 1959, the pickguard was changed from a white 1-ply with an 8-point fastener to a 3-ply with an 11-point fastener. With the pickguard change, the screw holes in the control cavity protrude, making it slightly narrower than before. This is the basic shape of the '60s.

The groove for the wiring cord in the rear pickup section has been cut at a certain depth with a rounded bottom, although it is freehand since around '57, although there are individual differences.

SwitchCraft" jacks are used. The edges of the cavities are shaved after painting, but there is a difference in the finish depending on the individual. There is what looks like a pin hole for jig fastening at the edge of the cavity, but it could not be confirmed clearly.

The datings on the body are marked on the spring cavity on the back, and it can be confirmed that it was made in '59.

After '57, the contour tends to gradually become shallower and shorter. The back contour has already been shortened from left to right. This is the part where there are detailed differences from year to year because of the detailed changes.

Neck pocket painted entirely. The lacquer peeling at the joints is consistent with the body and neck, so there is no doubt that this is an original set. Since around 1962, the neck pocket is painted with a hanger attached, so only half of the paint is applied.

Original pickups with black fiber paper above and below the bobbin. This pickup also remains untouched down to the masking tape that holds the wiring together. The magnet of the pickup is a cylindrical Alnico type V and the coil is "AWG (American Wire Gauge) #42". The pole piece is a "staggered" type with different height for each string to balance the volume, which was used until the mid '70s.
Alnico Type V: An alloy of approximately 50% iron with aluminum (Al), nickel (Ni), and cobalt (Co).
◎For your reference
(F)6.07kΩ (M)6.10kΩ (R)5.85kΩ

The serial number is one of the most important factors to identify the date of production. However, the serial number may not always match the date of production, since there are some pieces whose serial number and production date are extremely far apart for some reason, not to mention errors due to system changes including the production process, etc. The serial number is not always the same. Since some parts can be easily replaced, it is necessary to make a comprehensive judgment including each part in order to determine the actual year.

The pot is a round-groove type made by "Stackpole," which was adopted around 1957. The pot date is "304-5948," which identifies it as the 48th week of '59. The capacitor is a "CornelDubilier" 0.1μF 150VDC capacitor with no potting treatment from around '58. The switch is also an original 3-point type made by "CRL", which is characterized by its trapezoidal (rice-ball shaped) base.

In mid-1959, the switch was changed from 1-ply PVC to 3-ply white/black/white celluloid. The celluloid turned yellow with age and mixed with the dark blue (black but actually dark blue) in the center, giving it a greenish color, hence the nickname "green guard. The new 3-ply design also changes the aluminum shield plate on the back side, which used to cover only the control area, into a shape that covers the entire plate.

Rosewood fingerboard was adopted from mid '59 following Jazzmaster. In the early years, the fingerboard was made of slabs, and from the middle of '62, it was made of rounds, which were pasted together on a curved surface. Unfortunately, the neck date cannot be confirmed...

After the V-neck (triangular neck) up to '57, the guitar moved to a thinner, flatter grip from '58. This thin neck shape was also a feature until the early '60s.' With the standard rosewood fingerboard in '59, the walnut skunk stripe on the one-piece maple neck is no longer present.
◎For your information
<Neck size
Nut width: 42mm, 12th fret: 51mm
Neck thickness: approx. 21mm (at 1st fret), approx. 25mm (at 12th fret)

Kluson "covered" type pegs. Single-line Kluson pegs with "KLUSON DELUXE" engraved on them were used until around '63.

Gold color with black borders, commonly known as the "spaghetti logo. The headstock looks angular with almost no chamfering. No patent number until 1960, and only "WITH SYNCHRONIZED TREMOLO" on the bottom.

Spacers were added under the string guides in late '59. This reduces the load on the strings, resulting in softer string tension. This is a small detail, but it is surprisingly important.

You can see that the shape from the fingerboard to the headstock has changed with the introduction of rosewood. The maple fretboard has a steep curve, but the rosewood fretboard has a large, gentle curve.
For your reference
1st string side: 14mm, 6th string side: 14mm

From '59 to '63, "clay dot" position markers were used. In the middle of '63, the spacing between the two dot markers on the 12th fret was narrowed, and the side markers were changed as well.

The frets were pressed in from the top, but from this period, they were slid from the 6th string side to the 1st string side and set on the fingerboard.

The "bridge" and the "inertia block," which functions as a tailpiece, are integrated into one separate tremolo block. The name "synchronized tremolo" was derived from the fact that the integrated bridge plate and inertia block move synchronously when arming. From around 1957, a type with a deep groove for "FENDER PAT. PEND." engraved on the saddle was also adopted, but it seems that not a few of them are confused between the two.

Around '58, the pickguard (upper 11 screws) and jack (lower 2 screws) were changed from wood screws to tapping screws with a cutout all the way to the top. The neck joint and spring hanger screws remain wood screws. Serial number is engraved on the top of the neck plate.