Although the currently-available replacement late-type clip (2020) works perfectly well, it is not identical to the original. If you want to make your own, or modify the new type, the following collection of pictures might help.
The design allowed the front of the hood to be snapped into place with the conical ends of the windscreen support posts automatically pushing the spring-load keeper plates open. As the hood frame went slightly lower, the plates sprang into rectangular-shaped cut outs and the hood was locked in the down position. Each keeper plate was extended to form a lever that allowed then to be opened - and so the hood raised, a small hinged safety tab being provided to lock the levers in the closed position (a good job as it turns out, as over the years many units have suffered from weakened or broken springs.…)