it has the fender style neck pocket instead of the esp style neck pocket that is cut at an angle and vintage frets is appears to be the same as a 400 series,
if you are comfortable taking the neck off there is a chance it will have some information in the neck pocket or on the heal of the neck. I personally think these are
very high quality, I have owned two 400 series strats, as well as a seymour duncan strat made by esp, and a vintage plus. They are better than any modern
production fender in my opinion. I have seen the 400 series strats labeled, 400 , 400 series, esp ( with no other information), series, and now vintage series. I don't
have any catalogs that old, so I can't verify any dates. These were made from the early 80's until 1991. I still suspect this to be from the end of that run. It Should
have all stock esp hardware, and esp pickups. Compared to other strat pickups I have used they are good quality.