Barry is right:
JH2 - made in Japan
MEXXX - vehicle description code
X or (0-9) - check digit to ensure VIN is legal only
B, C, D etc indicates model year with B being 1981, C 1982, D 1983 onwards etc
Letter to signify plant produced in in respective country (A,B,C,D,E,F,K,M,R,S,T,4) - (Iains C was made in Saitama in Japan)
then sequential production number
So now if you can get the next letter - which should be E,F,G for 84, 85 or 86 you will have your answer.
Rossco