I have exactly the same wheels, with the vent wing inside.
Don't know if they're opel caliper but these are the one from the kit I bought 6 month ago, the same as the one showed in vw tech 19 pg 43 (sorry for the advert...).
The brand seems to be DELCO.
laurent 1st or 2nd generation are the same
vent wing inside each models , the only thing who change that there's 1 ribs behind the spokes of a first generation and 3 ribs on the second generation
check