I have been to see this car and spent a lot of time examining it. On the day I was there there was very little history available....to put it mildly. It seems the car was supplied as a l/w rolling shell by Autokraft and some years later was fitted with a Ford big block engine. I imagine that's when it was registered.
It's now described as a 428 and not a 427 side oiler. Shelby also used this engine in period, but it's not the same at all. The engine fit is more than a tight in the bay, but I've never seen how good any of the 11 factory cars are.
I remember AK offering rolling chassis at the end and some of the MK IVs in circulation today also had engines fitted after they left the factory. The question is, originality and motor spec aside, is it a usable, developed car? On a std rhd Mk IV, the drivers footwell moulding covers up the wing vent, as does the battery on the other side. Bad enough in summer traffic on a 5L 302, but a 7L? I can't see how this allows effective cooling. Some of the paint in the pedal box was blistered, but that might be normal. Does have 3" exhaust tubing, which is correct and very difficult to fit.
I thought it a fab looking car, despite having potentially some issues now and in the future.