How to find out actual build date for my Cavalier

[GrahamHardy]

Hi All

I'm new to this site so please be kind.

I own a Cavalier 1.8 Cabrio Auto registered 24 June 1986

Does anyone have an idea how I can find out the actual build date?

In speaking to another car buff he has advised me that if the the actual build date makes my car 40 years old I can apply to DVLA to et the Tax Class changed to Free of Charge.

Any tips and or advise welcome

Thanks in advance Graham