I don't know what to do about the buggered star. The belts should be V belts, some will be notched, all should fit in the pulleys with the V into the pulley (wider side out)).
Not sure what you mean by grooved, that sounds more like a serpentine belt, which will go around some pulleys with the grooves to the pulley and others with the grooves out. Our model year should have 5 separate belts rather than a single serpentine. I just went out and looked at mine and all 5 are notched on the inside, smooth on the outside.
What brand of belts did you buy?
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.