Man i cant believe famine didnt get it... I remember stumbling across this car when i was looking for another british car maker a long time ago... Last thread...
Its a Peerless GT (phase 1 i believe)
It could also be a Warwick GT
and the one with the buick engine would have to be the GT 350L
It is the Warwick GT. Almost the same as the Peerless and made by one of the Peerless founders. The way to tell them apart is that the Warwick has a one-piece front-end that hinges at the front - the Peerless has a bonnet (hood) and separate front wings (fenders). I'm sure that info will be useful to you one day.