The Plarail 255 series Boso View Express was actually first released ten years earlier than that, on 28th April 1995 in the ‘type 7’ box that had been introduced the year before. It was discontinued in 2002.
The 255 series was succeeded by the 257 series Boso Limited Express Sazanami, released as S-54 in a ‘type 9’ box on 16th June 2005. There is also a Plarail Shop edition from 2016.
The link given in the top post which shows a release later in 2005 is for the Plarail Day (14th October) limited re-issue of the 255 series. 2005 was the last Plarail Day, the first was 14th October 1997. This version has extra detail stickers on the front and a green JR printed on the sides of the cab that were not present on the 1995 one.
The original 1995 version of the 255 series is possibly easier to find in the UK than in Japan. This is because the identical model was released in Europe in 1998 in the Tomica World range as #7462 ‘Inter Rail’.
As @KNDYNT2099 says, the white plastic is prone to yellowing. Another thing to watch out for is that the black window strips on the sides of all three cars are separate pieces made of ‘smoked glass’ semi-transparent black plastic which can pop out and get lost. Examples seen for sale online sometimes have one or more of these missing. For example, here’s one I just found on ebay UK:
