Rekord update
Thanks for that useful information and for posting a really good picture of my car. Update is that I am considering fitting a 3.0 V6 manual gearbox engine from an Omega to this car along with a full restoration. I have bought the Omega, an ex-police car.
I am usually pretty fanatical about originality of classics but in this case the car model is not a special one such as a GS or GSE and the replacement I am considering is a Vauxhall one.
Plan is to paint it black, keep the interior as original as possible, but refit the seats with black leather, and fit some nice retro type wheels which will look good on the car such as Ronals.
I love my car because from the back she looks like a baby late 60's Dodge Challenger (like the one from Bullitt), and from the front somewhat similar to an Escort Mk1 with the rectangular headlights.