Behold. An mpeg of the Jeep on the extensive Matt Savage test track near Matlock.
Click on the question mark!
A chat afterwards confirmed that all was well. The gamble was that the gearbox, transfer box and axles may have been duff as these are the (only) parts not new, but they were fine. Even the radiator held water okay, but a laid back Californian mouse had made a nest in there some years ago. Debris cleared all was fine. Next is finish off the rear lights (me!) and give it a coat of paint, then an MOT.