Congratulations xviffer !

I have researched this for the benefit of anyone else,
and am pretty sure that this is the Connector used :
Tyco/AMP Econoseal J Series MK IIThe above link is to a US site where the Housing, Pins, Lock and Seals
can be purchased for USD $2.82 + Shipping, and could be used
to make up your own Accessory sub harness.
They are also available from other suppliers such as Mouser, RS Components etc.


Cheers
