Dating fender japanese guitars
The new Fender did not acquire any physical assets of the old company, just the name "Fender".
Hence during 1985 to 1987, production of Fender guitars was only done in Japan, while USA Fender created a new factory in California. BUT note that the "E" and "N" series does sometimes appear on "made in Japan" models. In any case, if it says "made in Japan", then it is... Fender has recently (in the last 20 years) introduced LOTS of different serial numbers schemes, depending on the country the Fender was made (USA, Mexico, Japan, Korea, etc). Sorry, since I do not collect new Fenders, I don't really keep track of these things.
The Fender Contemporary models were the first Fender Japan models to be exported as Fender Stratocasters and Telecasters.
The previous Fender Japan models exported from Japan were all Fender Squier models.
So, obviously a neck date, while being helpful in providing a date range of production, cannot be a definitive reference.
When CBS sold Fender to its current owners in 1984 there was a transitional period from 1984 to 1987 with limited Fender USA production resulting in mostly Fender Japan and leftover stock being sold.
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.
Black Francis used a Fender Contemporary Telecaster in the Pixies.
There were also USA Contemporary Stratocasters and Telecasters which were totally different than the original Japanese models in terms of features and construction.