I think what made them fun to tinker with was the simplicity of design. There was much you couldn't fix yourself provided you stay away from trying to adjust the Lucas voltage regulator. I loved the piston carbs, easy to work on, and you could fiddle with the air/fuel ratio by swapping needles. The solid brass fuel cutoff was gorgeous to look at until the natural cork packing died and you have to make a new on. Even the clutch and brake hydraulics were easy to work on compared to American cars.