finally I found real good chrome rings to mount my H4 headlights. The Bilux headlights which were mounted before, equipped with H4 sockets were o.k. - but a real good brand new H4 headlight is a different story.
Talking 'bout story, I bought the rings from an ebay auction together with "brand new H4 VW light units". Unfortunaltely the units were only Bilux style as well, the seller found the BOSCH boxes and the manual how to install the H4 inserts. But in the boxes were the only the replaced Bilux ones, which the seller wasn't aware of. He already offered to send some money back, which is fine for me. I already had brand new H4 units in the garage anyway, waiting for a nice set of 1-hole rings. Now I have the new H4 units together with the new rings mounted. Even if there is no big difference in looks (only 1 hole instead of 3 holes on the rings) - the light beam is so much brighter!
3 hole ring with Bilux style socket reflector:
1 hole ring with H4 socket reflector: