If you pay close attention, the Cibie Z-beam lens is actually almost completely different from the non-Z-beam Cibie lens. It has to be; the optical concept is very different. But it's unfortunately a moot point; Z-beams are sadly discontinued (avoid the "replica" ones, which are trash).
The Marchal Amplilux and its same-concept competitors from Cibie, Carello, Hella, and Bosch, with two bulbs and two reflectors behind a common lens, were the only way to have halogen low and high beam in a single headlamp -- the H1/H2/H3 came out in the early-mid '60s, but there was no 2-filament halogen bulb until the H4 came out in the early '70s. The Amplilux low beam was pretty good, but the high beam wasn't so great because of the small reflector (which nevertheless could be aim-adjusted independently of the low beam, making it a popular unit in some kinds of motorsport). The Cibie "Biode" had the opposite issue: a decent high beam but a poor low beam. Anyhow, this is moot too because all of these are discontinued.