Regarding quailty, I have owned many of both these Japanese guitars and it is a fallacy that the than the Mexican made guitars and rival many of the USA models.The JV and SQ guitars, as well as some of the E series, had USA parts (mostly pickups, switches, and potentiometers) that were shipped over to Japan to help speed up production while the new USA plant was being set up in Corona, California.Serial numbers are basically chronological, but there is some overlap in some years.Before the later 1970’s Fender never expected the guitars to be collectable or for serial numbers to be important.For instance, many of the MIJ/CIJ Telecasters have the serial number on the bridge and they start with an "A".Yet if you take the neck off they can be 1994-1997! well don't know the technicality but it boosts the highs and lows…I'm on three projects at the moment playing indie rock, funk and prog rock… The 1-piece maple neck was offered as a standard feature in 1997.

Also, some The Japanese serial number can be confusing too.

The Japanese-made Fenders do have some slight serial number differences (typically a "J" serial number prefix). I believe this was a mistake on Fender's part using the same prefix for both U. Below are some examples of letter prefixes used in recent serial number schemes.

Japanese Serial Numbers on Peghead Decal Note the lack of S, E, N series.

In March 1985, CBS sold Fender to a group of private investors.

The serial numbers do not reflect this change - Fender continued to make instruments using existing serial number schemes.