Find the owner

[Chipper]

Your best bet is to contact British Motor Heritage and obtain a Heritage certificate, which will give you all the original build details:

http://www.heritage-motor-centre.co.uk/ ... cates.html

Alternatively, DVLA may be able to provide some or all of the same info.

If you have the chassis number, you can trace the build year; this info is published in the book 'Morris Minor' by Paul Skilleter, though this site gives you a rough idea:

http://potteries.mmoc.org.uk/Identify.htm