Hi morierty, love these old cars between me and my old fella we had 4 Mk4 Zephyrs, first was a 1966 Ermine White V4 JVT 840D one of the first, second was a 1969 V4 deluxe in Met Green SUD 269G, third was a Black 1972 V4 deluxe XAM 264K ( i believe) and finally a 1972 V6 deluxe in Tawny Metalic.
One thing if the engine is original then I think you will find it will be a 2.5 Essex not 3.0 the latter was only fitted to the Zodiacs, Executives and I believe some of the Zephyrs used by the police, good luck with this project and keep the pics coming.
Regards RScapriman.