Just checked on the Morgan Registry and the car is listed there.
The colour is described as BRG, it is claimed to be 1973, and the owner making the entry was Del Richards, Tytherington, Cheshire, UK. His email address was given as suee@tesco.net.
I hope that enables you to track the car down, and I am sure the new owner will be pleased to receive any earlier documentation , but as ever, this data may not be up to date.
To other folk here, Tony's registry at
www.morganville.org is well worth spending a few minutes registering your car there. It helps keep track of cars all over the world